The invention relates to a device for cutting an elongate object, such as an offcut, and to a machine provided with such a cutting device.

Various machines, such as cutting presses and sheeters, are used in the paper processing industry.

In a cutting press pieces of paper and cardboard are punched to obtain a predetermined form and then for instance folded into a packaging such as a cardboard box. The residual material produced in such punching operations usually has irregular shapes, whereby this residual material will frequently become hooked behind something during discharge thereof, and result in malfunction. In practice such malfunctions usually occur multiple times per hour, and solving these malfunctions is labour-intensive and time-consuming.

A sheeter is a machine with which rolls of paper and thin cardboard are cut into sheets. In order to give the sheets right angles, a ribbon-like strip of paper or cardboard is cut off on the side of the roll during this cutting process. Such a ribbon is from several centimetres to about 10 centimetres in width and can be up to 1500 metres in length, and is thereby very difficult to handle.

Such a ribbon is on the one hand very thin and thereby has very flexible characteristics, whereby it is able to enter into small gaps and can become stuck there. Paper which is compressed can on the other hand form a very rigid build-up.

Such a paper strip of residual material of a cutting press, and in particular of a sheeter, is also referred to as an offcut.

The European patent application EP-Al-1 138 423, which is recognized as closest prior art, publishes a device for cutting an elongate object and is more particularly equipped to cut metal strips.

An object of the present invention is to provide a device for cutting an elongate object, such as an offcut, and a machine for processing elongate objects which is provided with such a cutting device.

Said object is achieved according to the invention with a device for cutting an elongate object, such as an offcut, comprising:

- a wall with a passage opening which is configured to feed therethrough the elongate object to be cut; and

- a blade movable along the passage opening substantially parallel to the wall, wherein the passage opening is at least partially clear during a stroke of the movable blade along the passage opening.

Because the passage opening is at least partially clear during a stroke of the movable blade along the passage opening, passage of the elongate object remains possible at all times. This is important because an offcut can reach very great lengths, and offcuts can be supplied substantially continuously. The cutting operation may not block this supply in such a way that the offcuts get stuck. An additional advantage is that a passage closed all the way round can be applied in combination with a blower because the passage opening remains at least partially clear during a stroke of the movable blade along the passage opening. Such a blower has been found highly suitable for displacing very long offcuts, such as spaghetti-shaped long ribbon-like strips of paper several centimetres in width and several hundred metres in length, toward the passage opening. It is noted that where reference is made in the following to offcuts, other elongate objects to be cut are also included.

Because the movable blade according to a preferred embodiment has an elongate form, it can on the one hand pass along the whole passage opening during an operating stroke, while the passage opening is at least partially clear during a stroke of the movable blade along the passage opening.

When according to a further preferred embodiment the one or more cutting edges of the movable blade are arranged at an angle relative to the peripheral form of the passage opening, the part of the passage opening which is clear during a stroke of the movable blade is enlarged.

Because of the oblique arrangement, the blade in each case covers only a part of the passage opening.

When according to a further preferred embodiment the passage opening is bounded on its underside and/or upper side by a fixed blade, cutting of the elongate objects is enhanced. The elongate object is cut by the movable blade moving relative to the fixed blade, corresponding to the operation of a pair of scissors.

According to a further preferred embodiment, the movable blade has two cutting edges and is configured to perform a reciprocal movement along the passage opening. The two cutting edges enable a blade to perform a cutting operation in both directions of movement of the reciprocal movement.

According to a further preferred embodiment, the passage opening is slotted and comprises a short and a long side, and wherein the movable blade moves transversely of the long side of the passage opening during a stroke and at least one of the short sides is bounded by an additional fixed blade. Particularly when the one or more cutting edges of the movable blade are arranged at an angle relative to the peripheral form of the passage opening will a part of the elongate objects to be cut be pressed against a short side. Cutting of the elongate objects on the short side is enhanced if this short side is also bounded by an additional fixed blade.

According to a further preferred embodiment, the fixed blades bounding the passage opening are arranged on the wall. According to yet another preferred embodiment, the passage opening and/or the one or more fixed blades have at least one rounded corner. If the one or more cutting edges of the movable blade are arranged at an angle relative to the walls of the passage opening, the object to be cut will move in a lateral direction during the cutting operation. Rounded corners are preferably provided in order to prevent the object to be cut being able to engage on an edge or groove.

According to yet another preferred embodiment, the passage opening is provided upstream with a passage, wherein a blowing device is provided which is configured to generate a downstream-directed airflow toward the passage opening, and wherein the passage comprises between the blowing device and the passage opening an infeed opening for feeding the elongate objects to be cut to the passage. Because the passage opening remains at least partially clear during a stroke of the movable blade along the passage opening, a passage closed all the way round can be applied in combination with a blower. Such a blower has been found highly suitable for displacing very long offcuts, such as spaghetti-shaped long ribbon-like strips of paper several centimetres in width and several hundred metres in length, toward the passage opening.

When according to yet another preferred embodiment the infeed opening of the passage comprises upward extending walls which define a drop bin, a very reliable transport to the cutting device is obtained even in the case of very long offcuts, such as spaghetti-shaped long ribbon-like strips of paper. The drop bin can be placed connected directly to a sheeter.

The guiding of elongate objects such as offcuts to the passage opening is enhanced when according to a further preferred embodiment the passage opening is provided upstream with a funnel-like passage.

In order to prevent the elongate objects catching on the funnel-like passage, according to yet another preferred embodiment this funnel-like passage is provided with at least one rounded corner. Still more preferably at least two opposite corners take a rounded form.

When according to yet another preferred embodiment the movable blade comprises a support part displaceable along a guide, the blade can be moved precisely and controllably along the passage opening and the optional fixed blades, this improving the reliability.

According to yet another preferred embodiment, an electric motor is provided for driving the movable blade via a drive rod arranged on an eccentric, wherein the eccentric is provided with a counterweight. The application of an eccentric is particularly advantageous because it provides a slow displacement at the end of the up and downward stroke.

When according to yet another preferred embodiment one or more compression springs are provided which are configured to be compressed by the support part in at least a lowermost extreme position of the movable blade, part of the energy of the downward stroke is reused for initiating the upward movement. This can spare the drive and increases the reliability of the cutting device. A safe cutting device, wherein at least the movable blade is shielded from users, is obtained if according to yet another preferred embodiment the wall forms part of a housing, wherein the housing accommodates the movable blade during the whole stroke thereof.

The invention further relates to a machine for processing elongate objects, comprising a cutting device according to the invention. Because the cutting device is integrated with the processing machine, cutting of the elongate objects into smaller parts can take place immediately after processing thereof. This reduces the transport of the elongate objects such as offcuts.

Preferred embodiments of the present invention are further elucidated in the following description with reference to the drawing, in which:

Figure 1 shows a perspective view of a cutting device according to the invention;

Figure 2 shows a cut-away perspective view of the cutting device of figure 1 ;

Figures 3, 4 A and 4B show perspective detail views of the cutting device of figure 1 ; and

Figure 5 shows a cross-sectional side view of an embodiment which can be connected to a sheeter.

The cutting device 1 shown in the figures is configured to cut an elongate object R, such as an offcut. Cutting device 1 comprises a wall 6 with a passage opening 8 configured to pass therethrough the elongate object R to be cut.

Cutting device 1 comprises a blade 32 movable along passage opening 8 parallel to wall 6, wherein passage opening 8 is at least partially clear during a stroke of movable blade 32 along passage opening 8 (Figure 2). This guarantees that passage of elongate object R is possible at all times. Passage of further elongate objects R even remains possible during a cutting operation of movable blade 32. This is important because elongate objects R, such as offcuts, can reach very great lengths of more than 1500 m and offcuts R can be supplied substantially continuously. The cutting operation may not block this supply in such a way that offcuts R or other elongate objects R to be cut get stuck.

Although it is possible to envisage cutting device 1 being integrated into a cutting press or so-called sheeter, it can also be supplied, as shown in figure 1 , as separate cutting device 1. Wall 6 in which passage opening 8 is arranged forms part of a housing 4, which preferably accommodates movable blade 32 during the whole stroke of movable blade 32. Movable blade 32 is hereby shielded from users, this increasing the safety.

The elongate objects/of fcuts R are supplied via a conveyor 60 to passage opening 8, and guards 62 are preferably provided adjacently of conveyor 60. A funnel-like passage 50 is preferably provided upstream of passage opening 8.

Preferably provided for driving movable blade 32 is an electric motor 56 which drives movable blade 32 via a drive rod 26 arranged on an eccentric 22. An eccentric 22 ensures that the speed of movable blade 32 is limited at the outer ends of the reciprocal stroke, this reducing the load and increasing the reliability of the device. The loads can be further reduced by providing eccentric 22 with a counterweight 24.

Movable blade 32 has an elongate form, and in the shown embodiment has two cutting edges 34, 36 so that movable blade 32 can perform a cutting operation both in a forward and a return stroke. Cutting edges 34, 36 of movable blade 32 are arranged at an angle a relative to the peripheral form of passage opening 8, this enlarging the part of passage opening 8 which is clear during a stroke of movable blade 32. This is because movable blade 32 in each case covers only a part of passage opening 8 because of the oblique arrangement.

As shown in the detail views of figures 2 and 3, passage opening 8 is slotted with a short side 14 and a long side 16. Movable blade 32 moves in reciprocal manner transversely of the long side 16 of passage opening 8 during a stroke. Passage opening 8 is bounded on its underside 10 by a fixed blade 42 and is bounded on its upper side 12 by an additional fixed blade 44. In the shown embodiment short sides 14 are also bounded by fixed blades 46. Fixed blades 42, 44, 46 which bound passage opening 8 are arranged on wall 6 and co-act with cutting edges 34 of movable blade 32, wherein elongate objects R are cut into cut parts R _c between movable blade 32 and fixed blades 42, 44, 46. By continuously moving movable blade 32 in reciprocal manner the two cutting edges 34, 36 alternately cut off objects R into smaller parts R _c .

In the shown embodiment movable blade 32 is arranged in a support part 38 which is displaceable along a guide 20. A filler piece 40 is provided in order to provide space for guide 20.

One or more compression springs 28 are preferably provided, which are compressed by support part 38 in the lowermost extreme position of movable blade 32. Support part 38 is in this way decelerated at the end of its operating stroke, and part of the downward energy can be reused in the upward movement.

The risk of objects R to be cut becoming stuck is reduced by providing passage opening 8 and/or the one or more fixed blades 42, 44, 46 with rounded corners 18. Funnel-like passage 50 is for this reason also provided with rounded corners 52.

As already described in the introduction, long ribbon-like strips of paper of several centimetres in width and several hundred metres in length are produced during operation of a sheeter. These very long spaghetti-shaped paper strands are extremely difficult to handle. The embodiment shown in figure 5 is configured to be connected to a sheeter (not shown). Passage opening 8 is provided upstream with a passage 50. A blowing device 54 generates a downstream- directed airflow B toward passage opening 8. Passage 50 is provided between blowing device 54 and passage opening 8 with an infeed opening 51 for feeding elongate objects R to be cut to passage 50.

Extending funnel-like passage 50 and providing it with upright walls 54 close to infeed opening 51 creates a drop bin 55 with connecting passage 50 to passage opening 8 of cutting device 1. The spaghetti-shaped paper strands R drop from the sheeter directly into drop bin 55 and are then displaced by a blower 54 in blowing direction B toward passage opening 8.

According to the invention, passage opening 8 remains at least partially clear during a stroke C of movable blade 32 along passage opening 8, whereby passage of elongate object R is on the one hand possible at all times. This is on the other hand however necessary in order to enable successful application of a blower 54. This is because the at least partially clear passage opening 8 prevents blower 54 generating an undesired pressure build-up in passage 50. If passage opening 8 were not always at least partially clear, additional air vents would have to be arranged in passage 50 in order to prevent undesired pressure build-up, and it is precisely these air vents which would form a new risk of malfunction as a result of paper strands R entering therein. In short, because passage opening 8 remains at least partially clear during a stroke C of movable blade 32 along passage opening 8, a passage 50 closed all the way round can be applied in combination with a blower 54.

Although it shows a preferred embodiment of the invention, the above described embodiment is intended solely to illustrate the present invention and not to limit in any way the specification of the invention. Where measures in the claims are followed by reference numerals, such reference numerals serve only to contribute toward the understanding of the claims, but are in no way limitative for the scope of protection. The rights described are defined by the following claims, within the scope of which many modifications can be envisaged.