The present invention relates to setting of corner protectors on a palletized load before or during wrapping of the load with film material. More precisely the invention relates to a method and an apparatus for setting the corner protectors.

When different kinds of palletized loads and articles are wrapped in film material with wrapping machines, some loads and articles require corner protectors to be added on the corners of the load in order to further protect the wrapped load. The corner protectors are generally set on vertically extending corners of the palletized loads and articles to be wrapped usually before or during the wrapping process. This way the wrapped film secures and keeps the corner protectors at their place.

The corner protectors are generally made of paper or paperboard material which is generally pre-folded so as to define a pair of surfaces which meet at an angle. The inner surface of the corner protectors are set against the load.

The known apparatuses for setting corner protectors on a load, which are used with wrapping machines that do not rotate the load to be wrapped, generally comprise in the each corner area of the load to be wrapped one or more mag- azines for storing and supplying corner protectors, and a pick-up or transfer mechanism for removing the corner protector from the magazine and transferring the corner protectors to the corner of the load. This type of an arrangement is disclosed in publication EP 1 033 305 B1 , for example.

Publication WO 2012/027705 discloses a corner post application system, which comprises at each of the four corners of the load to be enveloped a swing arm, an application arm coupled to the application arm, and a controller. The controller rotates the swing arm about a vertical pivot axis until a corner post held by the corner post gripper is aligned with adjacent sides that define a corner of the load. The controller thereafter stops rotation of the swing arm and moves the application arm linearly toward the corner of the load until the corner post comes in contact with adjacent sides of the load. The problem with these prior art corner protector setting machines is that they require four separate arrangements, one for each corner of the palletized non- rotatable load, in order to set the corner protectors to each corner prior to or during the wrapping process. This makes these prior art machines complex and costly.

The present invention provides a simple and cost-effective arrangement for setting corner protectors to each of the four corners of a non-rotatable load prior to or during wrapping of the load. Further, the present invention allows use of several different lengths of corner protectors for different heights of loads. In the present invention, the storages for the corner protectors are also located close to each other in the same area, which makes the refilling operations for the storages much simpler and easier operation than in the prior art solutions.

In the present invention, two corner protectors are taken from the corner pro- tector storage with an actuator comprising two gripper units, one for each corner protector taken from the storage, which then are given to a corner protectors transfer and setting device by the actuator. The corner protector transfer and setting device transfers the first two corner protectors other side of a load and sets the first two corner posts against the two vertically extending corners of the load furthest away from the actuator. After giving the first two corner protectors to the corner protector transfer and setting device, the actuator takes second two corner protectors from the corner protector storage, and sets them against the two vertically extending corners of the load closest to the actuator.

After the corner protectors are set against the corners of the load, the wrap- ping machine wraps a layer of film around the non-rotatable load, which film secures the corner protectors in their places. Now the actuator and the corner protector transfer and setting device can release their hold on the corner protectors, and the wrapping machine can proceed to wrap the whole load.

In the cases, where both of the two corner protectors taken from the corner protector storage have the same orientation and position, one of the two corner protectors need to turned to proper orientation in order to be able to properly set the corner protectors on adjacent vertically extending corners of the load. This turning or rotating is done advantageously by the actuator prior to giving the first pair of corner protectors to the corner protector transfer de- vice and prior to setting the second pair of corner protectors against the corners of the load by the actuator. For turning or rotating the corner protector to proper orientation, the actuator advantageously takes hold of the corner protector or protectors in the lengthwise middle area of the protector, so that the protector is easily rotated to proper orientation for example by rotating the actuator or the gripping portion of the actuator.

In the present invention the corner protector transfer and setting device may consist of two separate corner protector transfer and setting units, each unit handling one corner protector and covering one corner of the load. Advanta- geously these corner protector transfer and setting units are integrated in the structure of the wrapping machine.

The actuator used in the present invention is advantageously a robot equipped with two gripper units.

In the present invention the corner protector storage advantageously compris- es plurality of corner protector magazines for different types and lengths of corner protectors. Thus the type and length of the corner protectors used can be easily changed between different loads to be wrapped.

The features of a method according to the present invention are more precisely presented in claim 1 , and the features of an apparatus according to the pre- sent invention are more precisely presented in claim 4.

Exemplifying embodiment of the invention and its advantages are explained in greater detail below in the sense of example and with reference to accompanying drawing, which

Figure 1 shows a schematic top view of an apparatus according to an embodiment of the invention.

In the embodiment of Figure 1 the arrangement according to the invention for setting corner protectors for a load to be wrapped in film comprises a ring type of wrapping machine 1 , an actuator in form of a robot 2, two corner protector transferring and setting units 3, 3' integrated in the structure of the wrapping machine, and a corner protector storage comprising three corner protector magazines 4, 5 and 6. When the arrangement of the Figure is in use, the load to be wrapped is first moved in the wrapping area of the wrapping machine 1 with a conveyor line passing through the wrapping machine, for example.

After the load is placed in the wrapping area of the wrapping machine 1 , the robot 2, which is equipped with two gripper units, takes first two corner protectors, one with each gripper unit, from one of the corner protector magazines 4, 5 or 6, and gives the corner protectors to the two corner protector transferring and setting units 3, 3'.

Before the robot 2 gives the first two corner protectors to the corner protector transferring and setting units 3, 3', the robot rotates one of the corner protectors, for example around horizontal axis, so that the two corner protectors are in suitable orientation for setting them against the adjacent vertically extending corners of the load to be wrapped.

The two corner protector transferring and setting units 3, 3' transfer the first two corner protectors around or over the load in suitable orientations, and set the corner protectors against the two vertically extending corners of the load furthers away from the robot 2.

The corner protector transferring and setting unit 3, 3' comprise a gripping unit for gripping the corner protector handed to the transferring and setting unit by the robot 2. The gripping unit of the corner protector transferring and setting unit 3, 3' is connected movably in a horizontally extending guide, which allows the gripping unit to move from one side of the load to be wrapped to opposite side of the load. The gripping unit of the corner protector transferring and setting unit 3, 3' may also be rotatable and/or connected to the horizontally ex- tending guide through a lengthwise adjustable arm. Thus the corner protector can be turned to horizontal orientation when the corner protector is moved to other side of the load above the load and/or the corner protector can be moved sideways when the corner protector is moved to other side of the load in vertical orientation by the load. Once the robot 2 has given the first two corner protectors to the corner protector transferring and setting units 3, 3', it immediately returns to retrieve second two corner protectors from one of the corner protector magazines 4, 5 or 6. During the moving of the second two corner protectors to the load by the robot 2, the robot rotates one of the second two corner protectors into proper posi- tion for setting it against the other corner of the load. After these actions the robot 2 sets the second two corner protectors against the two vertically extending corner of the load closest to the robot. Since the robot 2 returned to retrieve the second two corner protectors from the corner protector magazine 4, 5 or 6 immediately after giving the first two corner protectors to the corner protector transfer and setting units 3, 3', both the robot 2 and the corner protector transfer and setting units 3, 3' set their respective corner protectors against the corners of the load substantially simultaneously.

When all four of the corner protectors are set against the respective corners of the load, the wrapping machine 1 wraps one round of film material around the load after which the robot 2 and the corner protector transfer and setting units 3, 3' release their hold on the corner protectors and the wrapping machine proceeds to wrap the whole load. After releasing their hold from the corner protectors, the robot 2 and the corner protector transfer and setting units 3, 3' re- turn to their stand by positions to wait for another load to be equipped with corner protectors.

The specific example provided in the description given above should not be construed as limiting. Therefore, the invention is not limited merely to the embodiment described above, but it can be modified in ways evident to a person skilled in the art within the scope of the attached claims.