WO2004007336A1

WO2004007336A1 - Method for descending and elevating rolls

Info

Publication number: WO2004007336A1
Application number: PCT/FI2003/000425
Authority: WO
Inventors: Seppo Sonninen; Matti Lammi
Original assignee: Raumaster Paper Oy
Priority date: 2002-07-15
Filing date: 2003-05-30
Publication date: 2004-01-22
Also published as: AU2003240889A1; FI113856B; FI20021384A0; FI20021384A

Abstract

A method for transferring paper rolls and cardboard rolls from an upper level (H1) to a lower level (H0) or vice versa. A transfer will take place in a substantially vertical direction. During the transfer, a roll/roll set (1) residing in the cradle (5) will be rotated around the swivel axis (11), which is located close to the load's centre of gravity, from a horizontal position into a vertical position or vice versa. The vertical movement and the rotation will take place at the same time. The invention is to replace hydraulic downenders/upenders that require a large operating space. The preferred actuator (8) for the invention is an electric motor.

Description

Method for descending and elevating rolls

The goal of this invention is to provide the method described in the introduction of claim 1 , by means of which paper rolls and cardboard rolls are transferred from an upper level to a lower level, for example, to a roll storage located on a lower floor or vice versa.

Currently, rolls are generally moved down by means of a downender that uses a 90° rotational movement to transfer a roll or a roll set from their horizontal position on an upper level to a lower level, thereby placing the roll/roll set into the vertical position.

Currently, the length of a roll set may be four metres, with their maximum weight being close to 10 tonnes. During transfer, the rolls rest within a cradle that may be provided with input and output conveyors with the associated drives. The descending height is typically about 5 - 8 metres. This means that a heavy load, in excess of 10 tonnes, may be located at a radius exceeding four metres from the swivel axis. The said load is transferred at a considerable velocity. The actuator is a hydraulic cylinder. To effectively manage the related inertial forces, and to provide sufficient hydraulic power, a power unit of about 45 kW will be required. This unit must be provided with an efficient heat exchange system. The hydraulic equipment with the associated ancillaries is very expensive. In addition, possible oil leaks may result in considerable damage in case oil is allowed to contaminate valuable paper rolls or leak into the environment.

Decelerating the load, which rotates at a high speed at a long distance from the support, causes considerable torque and forces that tend to loosen the downender from its foundation. This means that the support structures must be massive and connected to the foundation by numerous bolts. The high forces cause cracks in the structures.

Since the roll descending site is often located adjacent to a wall, and because the transfer on the lower level often continues in the direction of the wall, the downender construction and its principle of operation cause considerable expenses as follows.

In cases where the output conveyor, which moves perpendicular to the downender o peration l evel, i s located at a point where the downender delivers its load, a dead space will be formed between the conveyor and the wall. This dead space will be large, expensive, and difficult to exploit. On the other hand, if the output conveyor is located close to the wall, it will be necessary to use additional cross-directional conveyors to transfer the rolls, from the downender delivery point onto an output conveyor. The wall will also restrict the possibilities of using a counterweight.

In cases where the downender is unloaded in the direction of the rotation level, a roll, and especially a roll set, will have to be transferred relatively far, beyond the operating range, before the downender's reversing motion may begin. The prolonged waiting time must be compensated for by faster motion, which will increase the power requirement and costs. The purpose of this invention is to reduce the problems related to prior art.

The invention is advantageous with regard to its space requirement. Since a roll can be descended from its upper position in an approximately vertical direction, the operating zone will be reduced by about 50 percent, compared to that of a downender. The elevator can be unloaded in three alternative directions, and the reversing motion m ay b egin i mmediately once the roll/roll set has been unloaded from the cradle. The length of travel will be further reduced by the use of direct motion, instead of rotation. The operation speed can be reduced resulting in a decrease in the power requirement.

Due to the fact that the cradle swivel axis is located close to the load's centre of gravity, the inertial forces will remain insignificant. The power requirement will be reduced and lighter construction can be used. T he construction can also be made more durable than that of prior art. Moreover, no forces will be generated to loosen the equipment from its foundation. Consequently, the attachments and the foundation construction can also be lighter. To further reduce the power requirement, a counterweight can also be used, to compensate for the cradle portion of the load, for example. In this invention, a counterweight's inertial power increment will be essentially less than that of a d ownender. D ue to the reduced power requirement, t he hydraulic drive can be replaced by using a less expensive electric drive. This will eliminate the contamination problems, noise, and expensive hydraulic power unit with its space requirement, and the problems associated with warehouse temperatures.

The invention is based on moving a roll/roll set down from an upper receiving station to a lower deposit level, through a substantially vertical movement, and by rotating the load, during the vertical movement, preferably by force around the swivel axis, which is located close to its centre of gravity, into the vertical position. Alternatively, elevating will take place in the reversed order. More specifically, the invention is characterised by what is described in the characteristics section of patent claim 1.

The following is a detailed description of the invention, with reference to the attached drawings.

Fig 1. shows the side view of one embodiment

Fig 2. shows the side view of another embodiment

Figure 1 shows an embodiment that is applicable to even high elevating and descending distances. A descending application will function as follows. A roll/roll set 1 is brought by conveyor 2 into cradle 5 and is forwarded by the cradle-installed conveyor 3 against another conveyor 4 locating at 90° angle relative to conveyor 3, or against another obstacle. The conveyors are conventional slat conveyors, for example.

Cradle 5 connects through articulated joint 11 to carriage 7 that moves on guide rail 6. Carriage 7 is provided with sheave/pulley tackle 12. Sheaves 13 and 14 are attached to the top section of frame 15. Chain 16, which is attached at one end to the fixed construction, for example, to frame 15, goes via pulley tackle 12, sheave 13 and sprocket wheel 9 installed on the actuator's 8 shaft, and connects to counterweight 10 at the other end.

The other chain 17 is connected at one end to cradle 5, on the opposite side of the articulation point, seen from the roll, to connection point 19 and goes via sheave 14 and sprocket wheel 18 installed on the actuator's 8 shaft, and connects to counterweight 10 at the other end. Preferably, the said structures are located on both sides of the cradle.

Articulated joint 11 and attachment point 19 of chain 17 have been installed in such a manner that when cradle 5 is descended/elevated, the roll/roll set will turn 90° during the travel, due to the fact that the movement of articulated joint 11 measures 50 percent of the travel of attachment point 19. For example, with the difference in height between level H 1 and level HO being six metres, articulated joint point 1 1 may be located, in the upper position, 250 mm below level H1 , and at a distance of 2 m from conveyor 4. Thus, attachment point 19 will be located 1.75 m above level H1 and at a distance of 250 mm from conveyor 4.

The elevator has an identical construction and function but its direction of movement is opposite. An elevator with the above dimensions provides the opportunity of leaving the elevator sides open for loading/unloading to take place on level HO.

Figure 2 shows another embodiment for the invention providing a solution with the following functions.

The roll/roll set 1 is brought at level H1 , by conveyor 2 into the cradle, and onwards supported by conveyor 3 against conveyor 4 or another obstacle.

The cradle connects via articulated joint 11 to carriage 7 that moves on guide rail 6. The carriage is also provided with sheave/pulley tackle 12.

Chain 16, which is attached at one end to frame 15, goes via pulley tackle 12 and sprocket wheel 18 installed on the shaft of actuator 8, and via sheave 24 and connects to counterweight 10 at the other end.

The 90° rotation movement is produced by connecting rod 21 that is connected at one end through articulated joint 22 to attachment 23, which is attached to the fixed construction of the device, for example to guide rail 6 or frame 15. The other end connects through articulated joint 20 to the extreme upper corner of cradle 5 (in the lower position).

The preferred location for swivel axis 11 is slightly more than half of the maximum roll set height from conveyor 4 and about 0.2 m from the roll surface. The preferred location for the articulated joint point 20 from conveyor 4 is slightly more than the maximum roll set height, and slightly more than the maximum roll diameter from the conveyor 3.

The preferred length of connecting rod 21 is about 2/3 of the difference between the elevating/descending levels (H1 -H0). The preferred location for articulated joint point 22 is determined by the situation where the position of connecting rod 21 changes by about 90° during an elevating/descending operation.

The said dimensioning will allow the loading/unloading of a roll/roll set on the lower level at a 90° angle with respect to the travel direction on the upper level.

In cases where the said cross-directional loading/unloading is not required, then the preferred location for swivel axis 1 1 can be closer to the load's centre of gravity, when compared to the above. When sprocket wheel 18 that is installed on the output shaft of actuator 8, which is preferably an electric motor, is rotating, chain 16 will go via pulley tackle 12 and sheave 24, carriage 7 will ascend/descend and counterweight 10 will move in the opposite direction. During an elevating/descending operation, connecting rod 21 will force cradle 5 to turn 90° from the initial elevating/descending position.

The preferred weight of the counterweight is slightly below the total weight of the carriage and the cradle with the rolls removed.

The said devices are preferably located on both sides of cradle 5, in such a manner, however, that they have the actuator 8 in common.

Counterweight 1 0 is p referably l ocated i nside p rotective tube 25 which can also serve as a frame component.

The idea, which complies with this invention, can also be implemented using several other embodiments.

For example, actuator 8 can be attached to a drum as in cranes, into/from which the wire winds/unwinds. This solution is preferable in cases where the use of counterweight 10 is not desirable or possible.

The said chain 16 can be replaced by a toothed belt, a wire, etc. In addition, the solution can be based on using a rack and a screw. As an actuator, the electric motor can naturally be replaced by a pneumatic or hydraulic motor, a cylinder, etc.

The preferred implementation for the cradle 5 bearing is to use the said articulated joints 11 , however, a slew ring or a similar implementation is also possible. Therefore, the common term swivel axis is used when referring to the "articulated joint point".

Furthermore, there is also an alternative embodiment where carriage 7 is attached to the frame and the guide rail is mobile. In this case, articulated joint 1 1 is naturally connected to the guide rail.

Claims

Patent claims:

A method for transferring a paper roll or a cardboard roll/roll set

(I ) between different levels, for either descending them from an upper level (H1) to a lower level (HO) or for elevating them from a lower level (HO) to an upper level (H1 ), in which, method the roll/roll set (1 ) resting in a cradle (5) will be rotated from their horizontal position into the vertical position or vice versa, and in which m ethod the cradle (5) i s turned a round t he swivel axis

(I I ) and the swivel axis (11) is descended/elevated in a rectilinear direction, ch aracte rised in that the force required for the rotation and descending/elevating operations is produced by a single actuator (8), in such a manner that, during the vertical movement, the roll/roll set (1 ) is forced to turn from the horizontal into the vertical position or vice versa.

The method according to claim 1 , ch a racte rised in that the rotation is forced by a connecting rod (21 ), which is connected at one end (22) through an articulated joint to a fixed construction (23) and at the other end (20) to the cradle (5), and the length and articulated joint point locations (22, 20) so selected that, during the elevating/descending travel, the cradle (5) turns 90°.

3. The method according to claim 1 , ch a racte rised in that the force required for turning the cradle (5) is transmitted by means of a chain, belt, wire or similar.

4. A method according to any of the preceding claims, ch a racte ri sed in that the loading/unloading of a roll/roll set (1 ) on the lower level (HO) can take place in a substantially crosswise direction, compared to the loading/unloading direction on the upper level (H1 ).

5. A method according to any of the preceding claims, characterised in that the actuator (8) is an electric motor that is preferably controlled by a frequency converter.

6. A method according to any of the preceding claims, characterised in that the power requirement of the actuator (8) is decreased by using a counterweight (10).