Sawing device for sheets of wood, plastic or the like

A sawing device for sheets of wood and plastic material has a support with at least one transport belt. The transport belt has longitudinal profiled sections arranged in the transport direction of the transport belt. The longitudinal profiled sections are positioned at a spacing from one another. At least one saw unit is provided and is moveable transversely to a longitudinal extension of a sheet to be cut while the sheet is resting on the longitudinal profiled sections.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a sawing device for sheets of wood, plastic material or the like, comprising at least one saw unit which is movable transversely to a sheet positioned on a support.

2. Description of the Related Art

It is known to position sawing devices downstream of installations in which sheets are manufactured from individual lamella-shaped pieces of wood, wherein the sawing devices cut the sheets to the desired dimensions. The sheets produced in the installation are moved after a pressing step onto the support which is comprised of several, spaced-apart chains and pivotable support members on which the sheet rests during the sawing step. Such a support is expensive. Moreover, the arrangement of the pivotable support members on the chains requires that the position of the chains must be position-adjusted to match the different lengths of the sheets. Accordingly, it is frequently required to provide many such chains or their position must be newly determined for each installation.

SUMMARY OF THE INVENTION

It is an object of the present invention to configure the sawing device of the aforementioned kind such that the sheets can be cut or sawed simply and inexpensively.

In accordance with the present invention, this is achieved in that the support has at least one transport belt on which longitudinal profiled sections extending in the transport direction of the transport belt are arranged at a distance from one another.

In the sawing device according to the invention, the support comprises a transport belt on which longitudinal profiled sections are arranged. The transport belt is a cost-beneficial component which is favorable in regard to the costs for the sawing device. Since the longitudinal profiled sections extend in the longitudinal direction of the transport belt, their position is ideally arranged for any length of sheets to be cut or can be very simply adjusted for each new installation without constructive expenditure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The sawing device according to the invention serves for sawing sheets manufactured by a sheet bonding machine from individual pieces of wood.

An operator takes lamella-shaped pieces of wood2from a storage device or magazine1and positions them on a transverse transporter3which transports the pieces of wood2transversely to their longitudinal direction against a stop4. At the stop4the pieces of wood are transferred onto a transport device which transports the pieces of wood2sequentially in their longitudinal direction to a stop5or6. During this transport, an adhesive is applied onto one longitudinal side of the pieces of wood by means of a glue applicator7. As soon as the pieces of wood reach the stop5and6, respectively, the pieces of wood are moved by a slide transversely to the longitudinal direction onto a transverse conveyor8on which the pieces of wood are compiled to a lamellar package9by contacting one another with their longitudinal sides, as is known in the art. In the illustrated embodiment, the lamellar packages9and9′ can have different width. When the package9′ is to be produced with shorter pieces of wood, the stop6is moved out of the transport path of the pieces of wood2so that they are transported up to the stop5in the longitudinal direction and are moved by the transverse slide onto the transverse conveyor8. As is known in the art, the next piece of wood2is pushed with its longitudinal side, provided with the glue application, against the package9′ which is already positioned on the transverse conveyor8.

When the wider package9is to be produced, the stop6is moved into the transport path of the pieces of wood2so that they are transported up to this stop6in their longitudinal direction and are then moved by the transverse slide onto the transverse conveyor8.

In the described way, the packages9,9′ are compiled on the transverse conveyor8. Upon pushing the next piece of wood2against the already existing package9,9′, a counter pressure is generated, as is known in the art, so that the individual pieces of wood of the package9,9′ are firmly pressed together.

As soon as the package9,9′ has reached the desired length, it is moved into a press10which is actuated by a hydraulic device11. As soon as the respective package9,9′ has been moved into the press10, the corresponding pressing plunger is moved downwardly by means of the hydraulic device11and the package contained in the press10is pressed. In order for the glue between the pieces of wood to dry quickly, heat is employed during this pressing process.

It is possible to simultaneously press packages9,9′ in the press10. As soon as the packages9,9′ have been pressed sufficiently, they are released and the new package9,9′, which has been compiled on the transverse conveyor8during the pressing step, is now moved into the press10. When doing so, the pressed and dried package9,9′ which has already been pressed and dried in the press10, is moved by the next package still to be pressed into the sawing device10. In the sawing device12the packages9,9′ are sawed transversely to their longitudinal direction into individual pieces. The sawing device12has a transport unit13onto which the package9,9′ is moved after the pressing process. With the transport unit13the packages9,9′ which are to be cut are transported transversely to the longitudinal direction of the glued pieces of wood2.

The sawing device12has a transverse support14along which a saw unit15is movable. The transverse support14is moveably supported with its two ends on the longitudinal support beams16,17, respectively. The longitudinal beams16,17extend in the transport direction18of the transport unit13. As illustrated inFIG. 2, the longitudinal beams16,17are supported with their ends on vertical supports19,20which are resting on the floor21. The saw unit15has a circular saw blade22which is driven in rotation about a horizontal axis23.

For driving the transverse support14along the longitudinal beams16,17, drive motors24are provided which, as is known in the art, move the transverse support14with the saw unit15suspended therefrom parallel to the transport direction18in the direction of the double arrows25illustrated in the drawing (FIG.1). For moving the saw unit15perpendicularly to the moving direction25along the transverse support14, a stationary electric motor26(FIG. 1) is provided with which the saw unit15in the illustrated embodiment is driven by means of a chain drive. At the underside of the transverse support14two adjacently positioned linear guides27,28are provided which extend in the longitudinal direction of the transverse support14and from which the saw unit15is suspended.

The saw unit15has a horizontally positioned motor29with which the saw blade22is driven. The saw motor29is suspended from parallel piston rods30,31positioned at a spacing to one another which project from vertical cylinder housings32,33in the downward direction. They are arranged in the area adjacent to the transverse support14within the saw unit15. By means of the piston rods30,31the saw motor29is pneumatically lowered into the cutting position. The maximum travel stroke of the saw unit15along the longitudinal beams16,17is illustrated inFIG. 2at34. Since the saw motor29can be lowered into the cutting position, it is also possible to saw sheets of different width in a multi-track process.

The transport unit13downstream of the press10is adjusted to the length and the width of the sheet-shaped package9,9′ which is pushed out of the press. The transport unit13has a transport belt35which in the shown embodiment has a width of 2,500 mm and a length between approximately 2,000 and 3,000 mm. Of course, the transport belt35can also have other dimensions depending on the dimensions of the packages9,9′ to be sawed. It is also possible to provide two or more transport belts adjacent to one another and/or behind one another. The transport belt35is closed and has at its upper side strip-shaped profiled members36which extend across the entire length of the transport belt35and are welded or glued onto the transport belt35. Preferably, they are made of the same material as the transport belt35. Depending on the width of the transport belt35several such longitudinal profiled sections or members36are provided. In the shown embodiment, the longitudinal profiled sections36are provided at a spacing of approximately 100 to 150 mm and have, for example, a height of approximately 8 mm. The longitudinal profiled sections36extend over the entire circumference of the transport belt35in the transport direction18. The package9,9′ rests during the sawing process on these longitudinal profiled sections.

In order for the saw blade22not to destroy the longitudinal profiled sections36during the sawing process, the sections36are provided with at least one recess37through which the circular saw blade22can move during the sawing process. Of course, the recesses37of adjacent, spaced apart longitudinal profiled sections36are positioned at the same level. The width of the recesses37is, for example, 50 mm so that there is sufficient play for the circular saw blade22.

It is possible that the longitudinal profiled sections36have several recesses37positioned at a spacing from one another. These recesses37in all embodiments are advantageously of such a depth that they extend down to and meet the transport belt35.

The saw motor29with the circular saw blade22is in a lifted position when the package9,9′ is inserted into the sawing device so that the package9,9′ can be moved reliably onto the longitudinal profiled sections36of the transport belt35. The package9,9′ is moved onto the transport belt35by the new package moving into the press10. The package9,9′ moved into the press10and not yet pressed aligns the package being pushed out on the transport belt35so that the subsequent sawing cut can be performed without problems.

The transverse support14with the saw unit15is moved along the longitudinal beams16,17into the required position. Advantageously, for driving the transverse support14a motor24is provided on its two ends, respectively, so that the transverse support14can be moved properly in the travel direction25. The transverse support14is moved into the position required for transversely sawing the package9,9′. During this movement, the circular saw blade22is spaced from the package9,9′. Advantageously, the saw unit15is positioned at one end of the transverse support14. When the vertical supports19,20have a corresponding spacing from the longitudinal edges of the transport belt35, the saw unit15is substantially in the area adjacent to the package9,9′.

As soon as the circular saw blade22has reached the position required for the sawing cut, the saw motor29is lowered into the cutting position. The circular saw blade22is then positioned at the level of the recesses37of the longitudinal profiled sections36on the transport belt35, which has been moved before insertion of the package9,9′ within the sawing device12such that the recesses35are positioned at the level of the circular saw blade22. When the longitudinal profiled sections36are provided with only one recess37, the transport belt35moves one revolution until the recesses37are in the cutting position. After lowering the saw motor29into the cutting position, the saw unit15is moved along the transverse support14and the rotating saw blade22saws the package9,9′ by the required amount.

After completion of the sawing process, the transport belt35is driven such that the sawed-off sheet portion is transported away in the transport direction18.

As soon as the saw unit15with the transverse support14has been moved into a new cutting position, the transport belt35subsequently completes the remaining revolution until the recesses37are in the new cutting position.

When the longitudinal profiled sections36have several recesses, then it is not required to perform a complete revolution of the transport belt35. The belt35must be moved only into a position in which one of the recesses37of the longitudinal profiled sections36is positioned in the cutting position. The next cutting process can then be performed by moving the saw unit15along the transverse support14.

Since the recesses37of the longitudinal profiled sections36are always in the correct position during the cutting process, the longitudinal profiled sections36are not damaged by the circular saw blade22and therefore must also not be exchanged, as was required in the past for stationary devices.

Since the transport belt35has a closed support surface, cuttings will not drop down; they can be removed instead by suction from the transport belt35. If residual pieces should remain on the transport belt35, they are transported downwardly at the deflection location and can be collected there.

The longitudinal profiled sections36of the transport belt35advantageously have a minimal spacing from one another so that even short or narrow packages9,9′ rest in any position safely thereon and can be reliably transported.

The transport belt35is economical with regard to initial installation and ensures for any package length an optimal support action. The transverse support14is advantageously driven on both ends by drives which are preferably servo drives. The two drives are controllable independent from one another and connected to a control (not illustrated). It is ensured by means of the control that the drives move synchronously so that the transverse support14is aligned properly at a right angle to the longitudinal direction of the packages9,9′. This ensures that the wood packages9,9′ are cut precisely at a right angle. The cutting angle can advantageously be manually corrected if an error with regard to parallel alignment relative to the bonding seam should occur.

The transverse support14is connected at its ends with the longitudinal beams16,17such that it can be adjusted by small angles at a slant to the transport direction18, for example, within an angular range of ±7°. Accordingly, the package9,9′ can be sawed with slantedly positioned sides so that these sawed sheet pieces, for example, can be used for the manufacture of coffins where pieces of wood with slanted longitudinal edges are required.