Package making – With means responsive to a sensed condition – Of individual contents or group feed or delivery
Reexamination Certificate
1998-01-29
2001-06-26
Johnson, Brian L. (Department: 3628)
Package making
With means responsive to a sensed condition
Of individual contents or group feed or delivery
C053S466000, C053S449000
Reexamination Certificate
active
06250053
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the applying of wrapping sheets to pulp bales in which wrapping sheets are applied on each pulp bale during its transport between at least one upper and at least one lower conveyor.
BACKGROUND OF THE INVENTION
During the wrapping of pulp bales by means of two wrapping sheets, precut sheets or rolls are presently used, from which the sheets are cut in connection with the wrapping process. One sheet is thus transported to a lower folding position in a lower sheet pocket, and the other sheet is transported to an upper folding position in an upper sheet pocket. The sheets are positioned in such a way that, when the pulp bale is transported by a conveying belt between an upper and a lower conveyor, it comes into contact with the two sheets, whereby one on the upper side and one on the lower side of the bale follow along with the bale between the conveyors.
The lower wrapping sheet is clamped between the bale and the lower conveyor and in this way follows along with the bale in between the conveyors.
The bale height, however, can vary. In order to nevertheless ensure that the upper wrapping sheet in this case is also clamped between the bale and the upper conveyor, this conveyor has been inclined in such a way that the distance between the upper and lower conveyor decreases along the direction of transport.
The upper conveyor has thus been made resilient in such a way that a sufficient contact force is obtained, and the upper wrapping sheet thus follows along with the bale when the sheet is clamped between the upper conveyor and bale. The force, however, must not be so great that the bale is rigidly clamped and obstructed with continued passage between the conveyors.
While the bale together with the applied wrapping sheets is transported between the upper and lower conveyors, the sides of the sheet parallel to the conveying direction are folded inward towards the bale, and thereafter the bale is transported to a folding machine by a conveyor.
The problem with the present technology is that the upper and lower wrapping sheets, when the folding process is to commence, can be offset in relation to each other in the conveying direction. This displacement varies with the bale height and, thus, differs from one bale to the next. The displacement of the wrapping sheets can thus create problems in subsequent folding machines.
In the case above, the upper conveyor is inclined and the bale height varies, the point where the bale comes into contact with the upper conveyor for clamping the wrapping sheet can vary considerably. As a result, the upper sheet is displaced in relation to the lower sheet, because the lower sheet is always clamped at the same distance from the edge of the wrapping paper, while the upper sheet is clamped at different distances from the edge of the wrapping paper, depending on how far into the machine the bale has been transported before the bale comes into contact with the conveyor.
Due to the inclination of the upper conveyor, the contact force ensuring that the wrapping sheet is clamped is directed in such a manner that the bale is subjected to shearing forces. This, too, results in displacement of the wrapping sheets.
Another reason for such sheet displacement is that the conveyors advance the bale with varying force.
SUMMARY OF THE INVENTION
In accordance with the present invention, these and other objects have now been realized by the invention of a method for wrapping bales of pulp comprising transporting the bales between an upper conveyor and a lower conveyor, applying a first wrapping sheet to the lower surface of the bale as it is transported along a lower conveyor, applying a second wrapping sheet to the upper surface of the bale as it is transported along the upper conveyor, measuring the height of the bale prior to transporting the bale between the upper and lower conveyors, and adjusting the distance between the upper and lower conveyors based upon the measured height of the bale, whereby the first and second wrapping sheets are uniformly disposed on the upper and lower surfaces of the bale.
In accordance with one embodiment of the method of the present invention, the method includes sensing changes in the height of the bale during transporting of the bale between the upper and lower conveyors, and adjusting the distance between the upper and lower conveyors based upon the changes in the height of the bales.
In accordance with another embodiment of the method of the present invention, applying the first wrapping sheet to the lower surface of the bales comprises applying the first wrapping sheet from a lower folding position, and applying the second wrapping sheet to the upper surface of the bales comprises applying the second wrapping sheet from an upper folding position. In a preferred embodiment, the adjusting of the distance between the upper and lower conveyors includes adjusting the upper folding position.
In accordance with another embodiment of the method of the present invention, the method includes synchronizing the speed of the upper and lower conveyors.
In accordance with the apparatus of the present invention, apparatus for wrapping bales of pulp have been discovered comprising an upper conveyor, a lower conveyor juxtaposed with the upper conveyor, whereby the bales can be transported between the upper and lower conveyors, a transmitter for measuring the height of the bales upstream of the upper and lower conveyors, and positioning means for adjusting the distance between the upper and lower conveyors based upon the measured height of the bales, whereby wrapping sheets may be uniformly disposed on the upper and lower surfaces of the bales as the bales are transported between the upper and lower conveyors.
In accordance with one embodiment of the apparatus of the present invention, the upper and lower conveyors are substantially parallel to each other.
In accordance with another embodiment of the apparatus of the present invention, the apparatus includes a sensor for measuring changes in the height of the bales while the bales are being transported between the upper and lower conveyors.
In accordance with another embodiment of the apparatus of the present invention, the apparatus includes an upper sheet pocket for providing a wrapping sheet to the upper surface of the bales and a lower sheet pocket for providing a wrapping sheet to the lower surface of the bales, the upper sheet pocket being connected to one of the upper and lower conveyors, whereby the upper sheet pocket is simultaneously adjusted with adjusting of the distance between the upper and lower conveyors.
In accordance with another embodiment of the apparatus of the present invention, the apparatus includes synchronizing means for synchronizing the speeds of the upper and lower conveyors.
According to the present invention, the above-mentioned problems are solved by means of the position of the upper conveyor being adjustable in the vertical direction by means of a positioning device. This adjustment is carried out on the basis of values from a transmitter, which measures the height of the bale in connection with the infeed of the bale between the upper and lower conveyors. The upper conveyor is positioned such that its position in relation to the bale in question is always the same. The two conveyors can thus be arranged substantially parallel to each other.
A sensing device is provided to sense the force arising on the upper conveyor when the bale is between the conveyors. The value measured by the sensing device adjusts the position of the upper conveyor by means of the positioning device, so that the force on the bale is changed to the desired level. Also, this can be obtained by not driving the upper conveyor.
The speeds of the upper and lower conveyors are also synchronized. This ensures that the driving force on the bale in the conveying direction is the same on the upper side and the lower sides of the bale.
The upper sheet pocket, and thus the upper sheet, can follow along with the movements of the upper conveyor. In
Edström Tomas
Forhaugh Göran
Jonsson Age
Johnson Brian L.
Lerner David Littenberg Krumholz & Mentlik LLP
Luby Matthew
Valmet Fibertech Aktiebolag
LandOfFree
Method and device for applying wrapping sheets on pulp bales does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for applying wrapping sheets on pulp bales, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for applying wrapping sheets on pulp bales will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2504358