Package making – With means responsive to a sensed condition – Of receptacle or cover feed or adjunct feed or application
Reexamination Certificate
2000-08-09
2002-04-16
Rada, Rinaldi I. (Department: 3721)
Package making
With means responsive to a sensed condition
Of receptacle or cover feed or adjunct feed or application
C052S211000
Reexamination Certificate
active
06370839
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a stretch wrapping machine for wrapping a plurality of loads placed on a pallet with a plastic film in a stretched state.
For distribution and sale, products are often packed in a small unit in cartons or the like, and a certain number of packets (loads) are loaded on a pallet for shipping, cargo handling and storage.
Nevertheless, the loads on a pallet are likely to fall out of arrangement during shipping, cargo handling, storage, etc. Besides, product values may deteriorate during shipping, etc., because the pallet load may get wet by rain or the like or smeared with something like dirt. Further, some of the loads can be stolen during storage, etc.
Recently, in order to prevent palletized loads from falling out of shape and to protect them from rain, dirt, steal, etc., a polyethylene or other plastic film is wrapped around a plurality of palletized loads to provide so-called stretch wrapping.
As the stretch wrapping apparatus, there have been proposed some types of stretch wrapping machines. A turntable type stretch wrapping machine comprises a turntable for mounting a load, a carriage equipped with a feed roller for feeding a film, a mast for holding the carriage, and an elevator mechanism for raising and lowering the carriage along the mast. With a film roll set on the carriage and a pallet load placed on the turntable, the wrapping machine feeds a film along lateral surfaces of the pallet load by turning the turntable and moving the carriage upwards and downwards, so that the film is spirally wrapped around the pallet load [e.g. Japanese Patent Application Publication No. S59-9403 (JP-B-9403/1984)].
A rotary arm type stretch wrapping machine comprises a fixed table for mounting a load, a carriage equipped with a feed roller for feeding a film, an arm for revolving the carriage a round lateral surfaces of the pallet load, and an elevator mechanism for raising and lowering the carriage. With a pallet load placed on the fixed table, the wrapping machine feeds a film along lateral surfaces of the pallet load by turning the carriage around the lateral surfaces of the load and moving the carriage upwards and downwards, so that the film is spirally wrapped around the pallet load [e.g. Japanese Patent Application Laid-Open No. H8-156908 (JP-A-156908/1996)].
A rotary drum type stretch wrapping machine comprises a conveyor for carrying a long load, a carriage equipped with a feed roller for feeding a film, and a drum for rotating the carriage around lateral surfaces of the long load. With the leading end of the long load placed inside the drum, the wrapping machine feeds a film by rotating the drum while allowing the conveyor to feed the load at a fixed rate, so that the film is spirally wrapped around the long load.
Additionally, these types of stretch wrapping machine may apply a prestretch system. Such wrapping machine further comprises a stretch roller disposed opposite to a feed roller, so that a film is wrapped around a load in a prestretched state.
In the case of conventional stretch wrapping machines, operators have to perform analog volume controls in order to set various operational values such as the number of rotations of the rotation mechanism (e.g. number of turntable rotations), the feed rate of the feeding mechanism (e.g. carriage feed rate), the number of rotations of the feed roll, etc. Inevitably, the set values are heavily dependent on every operator's sense and variable from one operation to the other. Hence, it is difficult to maintain constantly good film wrapping conditions.
Besides, operators have to put considerable time in computing control amounts such as the number of rotations of the rotation mechanism, the feed rate of the feeding mechanism, the amount of film feed, etc. based on the data related to film wrapping such as film overlap amount and film wrapping tension.
In the case of the turntable type stretch wrapping machine, when the plane geometry of the load to be wrapped is square or rectangular, the film feed amount demanded on the load side (hereinafter referred to as the film feed demand) varies during the film wrapping process. By way of illustration, as shown in
FIG. 31
, when a corner
9
c
of a load
9
is rotationally displaced from a position near a film feeder
500
as shown in FIG.
31
(A) to a position shown in FIG.
31
(B), the film feed demand increases along with the rotational displacement. Similar variation of the film feed demand happens in the rotary arm type stretch wrapping machine.
Where the film feed demand varies, if the feed roller rotates at a fixed speed, the tension of the film fed onto a load changes in accordance with the film feed demand. As a result, the film cannot be wrapped around the load at an even tension. Besides, because of the tension change, a film may be tensioned at a corner of the load so strongly as to be torn. Otherwise, excessive film tension may damage the corner of the load or cause the pallet load to fall out of shape.
As described above, the film feed demand varies where a pallet load has a square or rectangular plane geometry. In addition, such variation may occur due to the kinds of loads, the loading conditions, etc.
From another aspect, when a failure occurs during operation, prior art stretch wrapping machines are designed to warn an operator of the failure by flashing a lamp or the like which indicates the type of failure. Upon noticing the failure, the operator performs a recovery procedure either by looking into the manuals, etc. for a proper operation corresponding to the lamp indication or by contacting a manufacturer for instructions.
Such conventional troubleshooting procedure is troublesome and time-consuming in discovering the proper recovery operation and eventually solving the problem. When the operator has to make contact with a manufacturer to solve the problem, generally by telephone, the operator often finds difficulty in explaining the exact state of the failure to the manufacturer, and has to wait for a long time before a person in charge of maintenance can give him a proper direction.
SUMMARY OF THE INVENTION
In a stretch wrapping machine which comprises a carriage for mounting a film roll, a rotation mechanism for producing relative rotation between the carriage and an article to be wrapped, a feed mechanism for displacing the carriage relative to the article, and a controller for controlling a drive for each of the rotation mechanism and the feed mechanism, and which is arranged to feed a film to the article by providing relative rotation between the film roll-mounted carriage and the article and to wrap the film around the article by displacing the carriage relative to the article, the present invention intends to ensure constantly good film wrapping conditions for various loads, regardless of the type, shape, etc.
To achieve this object, the present invention provides a touch panel input device for setting film wrapping data into the controller and allows the touch panel input device to provide digital presentation of the set data.
In the stretch wrapping machine of this invention, the data set by the touch panel input device relate to the number of rotations of the rotation mechanism (e.g. number of turntable rotations), a film overlap amount, a film wrapping tension, and the like.
Thus, the stretch wrapping machine of this invention allows the display of the touch panel input device to provide digital presentation (e.g. digital numeric value) of set values such as the number of rotations of the rotation mechanism, the overlap amount, the film wrapping tension and the like. Therefore, any operator can easily set or switch the wrapping conditions to the same values, without personal differences. As a result, good wrapping conditions can be constantly ensured.
Besides, the touch panel input device may have a function of displaying a screen for selecting any one of a plurality of programs which are set and stored in advance.
Further, the touch panel input device may have a function of
Nakagawa Kinta
Ogita Yoshimi
Ohira Toshiro
Ohya Tomotoshi
Takasugi Nobuyuki
Chukwurah Nathaniel
Rada Rinaldi I.
Rader & Fishman & Grauer, PLLC
Sekisui Jushi Kabushiki Kaisha
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