EP0133841A1 - Method and device for adjusting expanded wooden elements - Google Patents

Abstract

1. Method for aligning elongated wooden elements (1) in a predetermined way relative to at least one reference line (16) which is determined by at least one processing station (3, 4) to which the elongated wooden elements (1) are supplied one after the other in the longitudinal direction by means of a longitudinal conveyor (5) which in turn is loaded from an endless transverse conveyor (8) which conveys the elongated wooden elements (1) in the transverse direction wherein at least one optical scanning station (32) is provided in the conveyor area of the transverse conveyor for detecting the parameters which are characteristics of the elongated wooden elements and characterise their volumetric arrangement and can issue at a control point (15) signals representing these parameters for controlling position adjustment mechanisms for the elongated wooden elements (1) characterised in that the elongated wooden element (1) is brought by means of the transverse conveyor (8) into a longitudinal conveying position at a distance above the endless longitudinal conveyors (5), that the speed and/or conveying direction of the individual transverse conveyors (8) are controlled by the control unit (15) so that the elongated wooden element (1) is aligned into this longitudinal conveying direction in the predetermined way relative to the reference line (16), and that after the elongated wooden element (1) thus aligned has reached the longitudinal conveyor position the transverse conveyors (8) are stopped and lowered so that the elongated wooden element (1) is set down on the longitudinal conveyor (5).

Description

The invention relates to a method according to the preambles of claims 1 and 2 and an apparatus for performing these methods. Elongated wooden elements are, for example, boards, logs, beams, posts, moldings or the like or models or wooden parts for furniture or special wooden constructions.

The problem of aligning wooden elements with saws is already dealt with in DE-OS 23 21 309. The method described in this DE-OS and the device shown in it are intended to make it possible to reduce the waste of the valuable raw material wood to a minimum value. This known method can also be used in particular for producing dies or posts made of log blocks.

In the method known from DE-OS 23 21 309, use is made of a device which has a cross conveyor consisting of two parallel endless conveyors. On this cross conveyor, the wooden elements to be processed are fed to a longitudinal conveyor running perpendicular to it. This longitudinal conveyor is a roller or roller conveyor which has a number of spaced apart, parallel to each other conveyor rollers or rollers, on the top of which these wooden elements supplied by the cross conveyor are then fed to the processing station. In the area of the endless cross conveyor, an eprian scanning system is provided and this controls two position adjusting devices arranged on the longitudinal conveyor in alignment with the cross conveyor. These position adjustment devices are adjustable stops against which the wooden elements are placed by the cross conveyors in order to align these wooden elements on the rollers or rollers of the longitudinal conveyor with respect to the processing stations. In this device, the upper run of the endless cross conveyor and the common tangential plane of the rolls or rollers of the longitudinal conveyor must be in one plane. When the wooden element is fed to the longitudinal conveyor, the rollers of this conveyor must stand still so that the wooden elements can be placed on the position adjustment devices. Here, considerable frictional resistance can occur in the last conveying section, which is disadvantageous. It is also very disadvantageous that the position adjustment devices for adjustment are connected in series, fluidbetä have working cylinders. These position adjusting devices, which are practically stops, cannot be set arbitrarily continuously, but can only be set within interval steps. The smallest interval step is determined by the stroke length of the smallest cylinder. The wooden elements cannot be aligned exactly, but only assume an approximately aligned position within predetermined intervals. In addition, only adjustment by a mechanical stop is possible. A bumpless setting cannot be made.

Both the cross conveyor and the rollers or rollers of the longitudinal conveyor must be stopped. In order to convey the wooden element to the processing stations in the longitudinal direction, the longitudinal conveyor must then be driven. The wooden element, which is not exactly aligned with the processing station, can move even further out of the correct position with respect to the reference line when conveying on the roller or roller conveyor, which in turn is disadvantageous. Since no further guides are provided, transverse movement components scattering on the roller conveyor occur during transport.

In the older patent application DE-OS 32 17 281 a device for aligning a saw board, in particular a model, is described. A longitudinal conveyor is provided for the model, on which the model must be placed by hand. The model is aligned using laterally arranged rollers and fed to a measuring station. Before advancing the model to the Cutting tools should be aligned accordingly to ensure maximum yield. Cross-conveyors arranged between longitudinal conveyor sections are controlled by the measuring device, and they only have the task of shifting the wooden elements or models already arranged on the longitudinal conveyors somewhat sideways into a corresponding alignment position with respect to the cutting tool. A transport of the wooden elements on the longitudinal conveyor in a predetermined manner by means of a cross conveyor is not provided.

There is a need for a more precise and faster-working alignment method which works without an adjustable stop and according to a simple device for carrying out this method. The present invention is based on the object of solving the problems which arise here while eliminating the disadvantages of the known method and the known device.

According to the invention, this object is achieved by the method according to claim 1 and the device for carrying out this method.

Advantageously, the alignment is carried out by different movements and modes of operation of the cross conveyor carrying the wooden elements without a stop. These cross conveyors can, for example, rotate the longitudinal axis of the wooden elements in any desired manner about a vertical axis for aligning these wooden elements with respect to a predetermined reference line. The longitudinal conveyors are not roller conveyors but also endless conveyors, which run parallel to one another and at the same time exert constraining forces on the wooden elements after the takeover. These longitudinal conveyors do not have to be stopped, but can run continuously. With particular advantage, the upper runs of these longitudinal conveyors are trough-shaped down in certain areas and the controllable, liftable and lowerable transverse conveyors then extend through these areas. In a first operating position, in which their upper run runs above the upper run of the longitudinal conveyor, the cross conveyors can control the wooden elements into the aligned position relative to the reference line determined by the processing station. These wooden elements are thus in the longitudinal conveying position to the processing stations above the longitudinal conveyors. As soon as this aligned longitudinal conveying position is reached, the cross conveyors can be stopped and lowered in such a way that the elongated wooden elements are released onto the longitudinal conveyors in a shock-free manner. Depending on the shape of the elongated wooden elements, only movement quantities of the cross conveyors are controlled for a desired alignment, which in turn can carry out a controlled stop-start operation. It is no longer necessary to set mechanical stops that are not continuously adjustable in length, but can only be set to discrete interval positions.

Since no mechanical stops are provided, undesirable rebound effects are eliminated from the outset.

The optical scanning used to control the cross conveyors can be accomplished in the following manner. At several points in the transverse direction of the cross conveyor, actual positions or actual positions of certain parameters on the elongated wooden elements can be determined as they pass through the optical scanning stations. These parameters can be specific protruding or characteristic locations of these elongated wooden elements. These ascertained actual positions can then be compared in the control with predetermined target positions which are related to the desired alignment with respect to the reference line. The result of this comparison can be used to control the "movement of the cross conveyors in order to bring them into the desired position when conveying the elongated wooden elements. Thereby, since the conveyor speeds and the locations of the scanning and the conveying position above the longitudinal conveyor are known, the The controller automatically slows down and stops the cross conveyor when the wooden element has reached the longitudinal conveying position in the desired orientation with respect to the reference line, but micro-limit switches can also be provided for switching off when the elongated wooden element has reached this conveying position.

Another control possibility is that the running wooden elements are detected at a first scanning station by an optical scanner assigned to a cross conveyor, which then switches the assigned cross conveyor. In a further scanning station in the area above the longitudinal conveyor, a further scanning on each cross conveyor reduces the conveying speed. Finally, the associated cross conveyor is stopped by a limit switch. In the end position reached in this way, the transfer to the longitudinal conveyor then takes place by lowering the cross conveyor.

Of course, more than two, for example four or six, cross conveyors can be used. Advantageously, only the two outer cross conveyors located at the ends of the conveyed wooden elements are advantageously controlled by the control. The intermediate conveyors in between remain inactive. These cross conveyors can stand still in the lowered position. Optical scanning stations on the two operated cross conveyors control them in such a way that the wooden element is entered into the longitudinal conveying position on these two cross conveyors.

The lowering of the cross conveyors for transferring the wooden elements to the longitudinal conveyors can be carried out in a particularly advantageous manner in several stages in order to ensure a bumpless delivery to the longitudinal conveyors. In particular, the lowering can be carried out in two stages for simplification. A first fast stage is carried out, followed by a second slower stage for hanging up. On the one hand, this accelerates the operation and, on the other hand, ensures that the elongated wooden elements are placed on the longitudinal conveyor as smoothly as possible.

It can be particularly advantageous that the cross conveyors are fed by means of an upstream second cross conveyor. This second cross conveyor can feed the wooden elements from a supply or another processing station. In this way, the cross conveyors used for control, which extend directly into the longitudinal conveyors, can be kept optimally short. The longitudinal dimension then depends only on the desired alignment amplitude and the operating speed.

The optical scanning of the elongated wooden elements can take place in the area of the upstream second cross conveyor and / or in the area of the incoming cross conveyor running to the longitudinal conveyor. The controlling cross conveyors perform a controlled start-stop operation. These controlling cross conveyors are put into operation and controlled when an elongated wooden element is picked up. This commissioning can take place via the control. Corresponding signals can be supplied to the control from the optical scanning stations in the area of the upstream cross conveyor, which indicate that a wooden element is being fed to the incoming cross conveyor at a certain speed. If the distance of the optical scanning stations from the inlet of the controlling cross conveyor is known, the exact point in time at which the entry of the wooden element into this controlled cross conveyor takes place. A corresponding synchronous activation of the cross conveyor can then be carried out. But it is also possible at the entry point of this controlled cross conveyor To provide micro switching elements or optical sensors or other presence sensors that then trigger the start of these controlled cross conveyors. They are then stopped again in a controlled manner.

For trimming, d. H. To remove the tree edges from blocks, boards, planks or the like, upper and / or lower, leading and / or trailing cut surface edges can be optically scanned. If only one trimming cut is to be carried out at once, it is sufficient to scan an edge of the cut surface. However, it is also possible to use the method according to the invention and the device according to the invention simultaneously two opposite, ie. H. trimming parallel edges. Alignment can be carried out in such a way that either one edge lies optimally, or that both edges run somewhat obliquely to the processing stations in such a way that minimal losses ascertained by the control occur as a result of a predetermined alignment. With such an alignment method, both the leading and the trailing edge of the cut surface are scanned.

In the case of an optical scanning of both the leading and trailing cutting surface edge, the transverse distance of a further transversely displaceable processing station from the reference line can additionally be set for simultaneous processing of both edges of the wooden element. Such transversely movable processing stations are known per se and are available on the market.

Optical scanning methods that can be used are described for example in DE-OS 23 21 309 and in DE-PS 29 28 085.

According to the invention, a second solution to the above object is given by the method according to claim 2 and the device for performing this method.

This alternative method advantageously works with continuously running cross conveyors which can be driven by a single drive motor. Intermediate carriers are arranged next to each of the cross conveyors. The upper run of the cross conveyor can be lowered from a level above these intermediate supports to a level which lies below these intermediate supports and then raised in a controlled manner out of this back into the first-mentioned level. Furthermore, the intermediate supports can also be raised and lowered in a controlled manner together with the upper runs of the transverse conveyors within the regions of the trough-shaped deflection points of the longitudinal conveyors. In addition to each cross conveyor, two optical scanning stations are provided one behind the other in the conveying direction. If an elongated wooden element with a characteristic parameter, for example with a certain point on the leading edge, first passes through any of the first optical scanning stations, the running speeds of all cross conveyors are reduced. The wood element then continues to run and as soon as any characteristic point is detected by the second scanning station, the entry of this point into the end position, the drive connection between the assigned cross conveyor and the wooden element is interrupted. At this point, the wooden element is not conveyed further, but is simultaneously placed on an intermediate support. Such an interruption of the drive connection can be carried out in such a way that first the upper run of the cross conveyor runs above the intermediate carrier and that this upper run is lowered below the upper or supporting edge of the intermediate carrier to interrupt the drive, so that at this point the wooden element on this intermediate carrier is discontinued. This process is now repeated in any order for all other cross conveyors until the last drive interruption has occurred, ie until the upper run of the last cross conveyor is lowered below the assigned intermediate carrier.

This method enables a considerable simplification of the expenditure on equipment while at the same time maintaining an optimal alignment accuracy. Only two scanning stations are required per conveyor and there is only a mechanical action on the upper run of the cross conveyor and on an assigned intermediate carrier. The mechanics required for this can be made extremely simple and robust. Furthermore, it is possible to run this method at high working speeds because, due to the two-stage running speed, work is only carried out at low conveying speeds in the short settling interval.

The device for carrying out the method has endless longitudinal conveyors which are arranged parallel to one another. In principle, roller conveyors are not used. In order to enable problem-free feeding by means of endless cross conveyors, these longitudinal conveyors each have in the upper run at least two groups of regions which are formed at a distance from one another and are arranged in a line perpendicular to the conveying direction. In these areas, the upper runs are guided in downward, trough-shaped guides. The lifting and lowering and controllable cross conveyors can then extend through these areas. The cross conveyors can cross the longitudinal conveyors at any heights above, below and in the conveying plane of the upper arms of the longitudinal conveyors, without interfering with the longitudinal conveyors which are operated continuously.

In particular, the downward, trough-shaped guides can be sliding guides, the inlets and outlets of which lie in one plane. These sliding guides can advantageously consist of a friction-resistant, self-lubricating plastic material. This enables simple production of the longitudinal conveyor with a guarantee of trouble-free operation.

The endless longitudinal conveyors can advantageously be chain conveyors that carry pointed drivers that guide the wooden element. All longitudinal conveyors can be driven by a single drive motor. This considerably simplifies the entire structure of the system. It would result in a much more complicated drive structure if each between the Cross conveyors are arranged in self-contained endless longitudinal conveyor sections, which would have to be driven separately and synchronously with each other.

In order to ensure a bumpless and safe introduction of the wooden elements into the processing stations, a hold-down device for the elongated wooden elements can extend in the area of the discharge ends of the longitudinal conveyor between these and the inlet end of the processing stations. With particular advantage, this hold-down device can be designed as a drive in order to ensure a safe supply of the wooden elements into the processing stations. This is of particular importance for shorter wooden elements, since an inevitable transport to the processing station is ensured.

The cross conveyors can advantageously be designed such that the upper and lower run of these cross conveyors extend through the trough formed by the trough-shaped guide. However, it is also advantageously possible that, as an alternative embodiment, only the upper run of the cross conveyor runs through the trough formed by the trough-shaped guide. The associated lower run goes under the guide sole of the trough-shaped guide, so that the cross conveyor practically grips or circles around the longitudinal conveyor in this area.

With the first-mentioned method, each cross conveyor can be mounted with particular advantage in a frame that can be raised and lowered by means of fluid-operated working pistons. These pistons can be pneumatic or be operated hydraulically and controlled by the control system. Each incoming cross conveyor is driven by a motor that can be controlled by the control.

Each cross conveyor can also advantageously be a chain conveyor, which in particular has pointed drivers that guide the wooden element.

At least one optical scanning station is assigned to one or both cross conveyors. The arrangement and design of these scanning stations depends on the desired mode of operation.

Height-adjustable light scanners which emit a light beam perpendicular to the conveying device and which have a precisely defined measuring beam length with background suppression are preferably used with particular advantage in the optical scanning stations. The cutting surface edge between the upper and lower cutting surface and the tree edge is detected in a reliable manner. This scanning depends on the thickness of the wooden element and responds when a predetermined or target thickness is reached.

The device for performing the alternative method is designed so that the upper run of the cross conveyor is guided in a guide rail. A holding rail can now extend along this guide rail as an intermediate carrier. The guide rail can be raised and lowered relative to the holding rail, so that the upper run of the cross conveyor can be raised and lowered so that a wooden element carried by it during lowering can be placed on this support rail. Furthermore, the holding rail and the guide rail can be raised and lowered together. There are numerous design options for this. For example, separate and particularly controlled working pistons can be provided for the guide rail and holding rail, which carry out the common and mutual lowering.

A particularly simple and robust embodiment has an angle lever on two parallel shafts. These angle levers have legs extending downwards and these legs of the two angle levers are connected to one another via a push rod so that they can be pivoted together. One of these downwardly extending legs is connected to a drive piston. If this drive piston is operated in a controlled manner, the angle levers are pivoted in a corresponding manner. These angle levers have approximately horizontally extending legs and each of these legs has two articulation points for carriers, for the holding rail and the guide rail. These carriers are each connected to the holding rail or the guide rail at corresponding points, for example in the vicinity of the ends. The articulation points of the carriers for the holding rail are at a smaller distance from the shaft than the articulation points of the carriers of the guide rail. In this embodiment, if the angle levers are pivoted, the carriers of the guide rail perform a larger stroke than the carriers of the holding rail because of the greater radial distance from the shaft. This can result in a Initial pivoting of the angle lever, the guide rail relative to the holding rail are lowered so far that the upper run of the cross conveyor gets to lie under this holding rail. The movement can then be stopped in a controlled manner. In the final phase, when the angle lever is pivoted further, the guide rail and the holding rail are lowered together. The wooden elements are placed on the longitudinal conveyor.

The deflection rollers of the cross conveyors are installed in a fixed position and a deflection roller set is driven by a single drive motor that can be controlled. The upper edges of the holding rails can carry spikes to securely hold and guide the wooden elements.

In this embodiment, the cross conveyors, which can be chain conveyors, necessarily have a sag. The cross conveyor belts can be spread by spring force. Approximately in the middle of the cross conveyor, a compression spring can be provided, which is supported at one end on the guide rail and the other end carries, for example, a sliding shoe which is supported on the lower run.

• Fig. 1 eine schematische Draufsicht auf ein Ausführungsbeispiel einer Vorrichtung zur Durchführung des Verfahrens,
• Fig. 2 eine schematische Schnittansicht genommen längs der Linie 11/11 der Fig. 1, wobei für das Verständnis nicht erforderliche Teile wie insbesondere Maschinengestell, Antriebsverbindungen und Lagerungen fortgelassen wurden,
• Fig. 3 eine schematische Schnittdarstellung genommen längs der Linie III/III, in der das Prinzip der Fördertrummumlenkung veranschaulicht ist,
• Fig. 4 eine schematische Schnittansicht einer erfindungsgemäß bevorzugten Lichttastvorrichtung, die als Abtasteinrichtung in einer optischen Abtaststation verwendet wird,
• Fig. 5 eine schematische Schnittansicht einer Ausführungsform des Querförderers und
• Fig. 6 eine schematische Ansicht des Querfördererabschnittes gesehen von der Linie A-B der Fig. 5

The invention will be explained in the following description with reference to the FIG. Of the drawing. Show it:

• 1 is a schematic plan view of an embodiment of an apparatus for performing the method,
• 2 shows a schematic sectional view taken along the line 11/11 of FIG. 1, parts which are not necessary for understanding, such as in particular the machine frame, drive connections and bearings, being omitted,
• 3 is a schematic sectional view taken along the line III / III, in which the principle of the conveying strand deflection is illustrated,
• 4 shows a schematic sectional view of a light scanning device preferred according to the invention, which is used as a scanning device in an optical scanning station,
• Fig. 5 is a schematic sectional view of an embodiment of the cross conveyor and
• 6 is a schematic view of the cross conveyor section seen from line AB of FIG. 5th

1 and 2 schematically illustrate a device with which a wooden element 1 to be trimmed for trimming work stations 3 and 4, which are arranged in a frame 2, is to be supplied. The trimming of the wooden element 1 should be optimal, d. H. it should be worked with a minimal loss. For this purpose, certain edges of the wooden element 1 must be arranged in a predetermined manner in relation to the work stations. In order to carry out such an arrangement, this wooden element 1 is aligned with respect to a reference line 16. In the exemplary embodiment shown, this reference line 16 is determined by the processing station 3.

In the exemplary embodiment shown, wooden elements 1 are controlled from a supply by means of cross conveyors 17 and fed to the incoming cross conveyors 8. These cross conveyors 17 comprise individual endless conveyors 52 which are deflected at 54. These deflection points 54 can lie between the cross conveyors 8, so that the wooden element 1 can be discharged from the cross conveyors 17 onto the cross conveyors 8 in a simple manner. The cross conveyors 8 extend towards the longitudinal conveyors 5, which have the task of feeding the elongated wooden elements 1 to the processing stations 3 and 4 in an aligned manner. Each cross conveyor 8 is mounted in a frame 30 which can be raised and lowered in a manner to be described by means of fluid-operated cylinders 29.

The longitudinal conveyors 5 are also endless conveyors. Both conveyors 5 and 8 are preferably chain conveyors and can have pointed drivers, which are shown purely schematically at 34 and 51. These pointed drivers capture the wooden element so that it can be guided safely. A controllable drive motor 31 is provided for each conveyor 8, so that the individual transverse conveyors 8 can be driven independently of one another at different speeds and / or conveying directions.

Of particular importance is the formation of those points at which the cross conveyors 8 cross the longitudinal conveyors 5.

As shown in FIG. 3, the upper runs 6 of the longitudinal conveyors 5 are trough-shaped, for example V-shaped or U-shaped, deflected downward in regions 11 which lie in a line in the conveying direction. For this purpose, troughs in the area of the upper run 6 are on the frame, not shown, which carries the longitudinal conveyor 5 shaped guides 24 are provided, the inlet 25 and outlet 26 are at a height. The upper run 6 of the longitudinal conveyor 5 runs in front of the inlet with its conveying surface in the plane 14 and after it runs out of the guide 24, this again runs in the plane 14, as is shown schematically in FIG. 3. The guide 24 has a guide sole 27 to which the upper run 6 is led down. From there the upper run 6 runs up again. This guide 24 is preferably a sliding guide and can be made from a friction-resistant, self-lubricating plastic. This simplifies the manufacture of this guide. At the same time, the operating time is increased.

3, the sole section 27 is so wide that a cross conveyor 8 can extend transversely through the trough 28 which is formed by the guide 24.

The arrangement can be such that both the upper run 9 and the lower run 10 of a cross conveyor 8 pass through this trough 28. However, it is also possible, as shown schematically in FIG. 3, to design the system in such a way that the upper run 9 of a cross conveyor 8 extends through the trough 28. The lower run 10 'runs below. through the sole portion 27 of the guide 24. The cross conveyor 8 encompasses or rotates the upper run 6 of each longitudinal conveyor 5.

The cross conveyor 8 can be raised and lowered in these areas 11. Raising and lowering takes place using the Working cylinder 29, which can raise and lower each frame 30. In an upper position of the cross conveyor 8, the conveying surface of the upper run 9 of the cross conveyor 8 lies in a plane 13 which is clearly above the plane 14 in which the conveying surfaces of the upper run 6 of the longitudinal conveyor 5 run. In this position, the wooden elements 1 are introduced by the cross conveyors 8 into the longitudinal conveying position above the longitudinal conveyors 5. When this longitudinal conveying position is reached, operation of the cross conveyor 8 is stopped, as will be described later. Then the cross conveyors 8 are lowered. After the single or multi-stage lowering of the cross conveyors 8, the level 13 of the conveying surface of the upper run 9 of these cross conveyors 8 is clearly below the level 14 of the conveying surfaces of the upper run 6 of the longitudinal conveyors 5 inevitably wooden elements 1, which are entered by the cross conveyors 8 in the longitudinal conveying position, placed on the longitudinal conveyors 5. The longitudinal conveyors 5 are driven continuously.

Hold-down devices 33 are provided between the discharge ends of the longitudinal conveyors 5 and the entry end of the processing stations 3 and 4, which can be designed as a drive. These hold-downs 33 are used to feed the aligned wooden elements 1 to the processing stations in the correct manner. This is particularly important for short wooden elements.

For the operation of all longitudinal conveyors 5, only a single drive motor 35 is required.

1 and 2, optical scanning stations 32, 32 'are provided. These optical scanning stations can be arranged above the cross conveyor 17 and / or the cross conveyor 8. The arrangement and design of these optical scanning stations depends on the desired mode of operation.

In the exemplary embodiment shown in FIGS. 1 and 2, the optical scanning station 32 can determine the actual geometric position of the wooden element 1 with respect to the reference line 16 at various points in the transverse direction of the wooden element 1. Corresponding signals are then fed to the controller 15 via a line 54. A program can be fed into this control, for example, that contains the desired position of these points of the wooden element 1 with respect to the reference line 16. The controller determines the difference values between the actual and the target position. On the basis of these difference values, command signals are sent to the controllable motors 31 via the line 56. Depending on the misalignment of the wooden element 1, these command signals can, for example, give the command that the external cross conveyor 8, that is to say the ends of the wooden element, are operated in a very specific manner. Thus, the cross conveyor 8 on the left can be moved in succession at different speeds in the top view in FIG. 1, and the cross conveyor 8 on the right can also be moved. The intermediate cross conveyor 8 remain inactive. These cross conveyors 8 remain lowered and are not driven. This enables the desired alignment with respect to the reference line 16 to be adopted. The duration of the controlling Action of the cross conveyor 8 is determined by the controller 15.

This mode of operation can, however, also be controlled by optical scanning stations assigned to the individual transverse conveyors 8 and arranged one below the other along these transverse conveyors. These scanning stations can determine the entry of an edge section of the wooden element 1 on the cross conveyor 8 and can start the motor 30 of the associated cross conveyor at a predetermined speed. This control takes place depending on the entry of an edge section at the other cross conveyor (s) 8. Further optical scanning stations can change the speed of the assigned motors when the section of section passes or stop the motor at the end entry into the end position.

The controller 15 can also put the motors 31 into operation when the wooden elements 1 are placed on the cross conveyor 8. When passing through the optical scanning station 32, a presence signal can be transmitted to the controller 15. Since the controller knows the distance from the point at which the presence signal is taken from the inlet of the cross conveyor 8 and the conveying speed of the cross conveyor 17, the controller 15 can switch on the conveyor 8 at the right time and control it as required.

The cross conveyor 8 can also be switched on, if desired, via microswitches or other optical and electrical sensing elements.

As soon as the wooden element 1 has reached its correct longitudinal conveying position, which is predetermined by the reference line 16, above the longitudinal conveyor 5, stop signals are supplied to the motors 31 by the controller 15 via the line 56 or by other optical scanning stations. The pumps 57 can receive command signals via the lines 56, which cause the fluid-operated cylinders 29 to lower the frames 30 in one or more stages. The cross conveyor 8 are taken along in the manner described above.

In order to ensure a smooth placement of the wooden elements 1 on the longitudinal conveyor 5, which run continuously, the frames 30 and thus the cross conveyor 8 are lowered in stages. In particular, the lowering can be programmed in such a way that this takes place in two stages. In a first stage, it is quickly lowered until the level 13 lies just above the level 14. The lowering is then slowed down in order to enable the wooden element 1 to be placed gently on the longitudinal conveyor 5.

If both edges of the wooden element 1 are to be trimmed at the same time, the wooden element 1 can be brought into a predetermined position with respect to the reference line 16 with one edge. This reference line 16 is determined by the processing station 3. In order to trimm the edge parallel to this, after a width measurement of the wooden element 1 by the optical scanning stations, a command signal can be issued by the controller 15 via line 58 to the transversely displaceable processing station 4. The distance D from the reference line 16 so that the other edge of the wooden element 1 can be trimmed optimally.

The actual position of the wooden element 1 can be optically scanned above the cross conveyor 8. Furthermore, additional optical scanning stations, which are arranged in the transverse direction to the transverse conveyors 8 and 17, can be provided. These can enable a fine correction after a rough correction or determine whether the target position has been reached.

The optical scanning is preferably designed such that the entry of the wooden element 1 into the end position is determined at a predetermined point. Certain cross conveyors are stopped one after the other. Other cross conveyors continue to be operated in order to bring other points of the wooden element into the correct end position, so that the desired orientation with respect to the reference line 16 is finally achieved. In particular, this operation is carried out only with two cross conveyors, which are determined by the length of the wooden element 1.

With a basic concept of the device - continuously rotating longitudinal conveyors 5, which are traversed in the transverse direction by controllable, lifting and lowering transverse conveyors 8 - the most varied of tasks can be solved. The optical scanning stations can be designed and arranged for this in the simplest way. Furthermore, the control can be designed as required.

A plurality of such devices can be arranged one behind the other in order to carry out bending and trimming and then obliquely cutting corners or the like.

The special interlocking of controlling cross conveyors _UJ longitudinal conveyors 5 enables a continuous and secure alignment of the elongated wooden elements with respect to processing stations and a precisely aligned supply to them. This alignment is not only limited to gradually adjustable, approximate values. Furthermore, the use of endless conveyors, in particular chain conveyors, with drivers penetrating into the wood maintains the correct alignment position achieved during further conveying. When the elongated wooden elements are transferred from the cross conveyors to the longitudinal conveyors, there are no harmful friction effects. It is also no longer necessary to produce an edge system with its uncertainties for alignment.

Optical scanning stations that can be used in the subject of the invention are described, for example, in DE-OS 23 21 309 and in DE-PS 29 28 085.

In the illustration in FIG. 4, a wooden element 1 is conveyed on the cross conveyor 8 or 17. This wooden element 1 has an upper cut surface 22 and a lower cut surface 23 which determine the cut surface edges 18, 19, 20 and 21. This wooden element has so-called tree edges 37 and 43, which are cut off during trimming. The cutting should be like this take place that the smallest possible loss occurs, that is, as close as possible to the upper cut surface edges 18 and 19. The edge 18 is the leading edge and the edge 19 is the trailing edge.

Depending on the rogram, the cross conveyor 8 can also be controlled in such a way that, for example, a maximum area or space meter yield is obtained from the blanks.

Instead of the described devices known from DE-OS 23 21 309 and DE-PS 29 28 085, the preferred light scanning device shown in FIG. 4 can be used in the optical scanning stations according to the invention.

A plurality of light scanners 57 are arranged transversely to the conveying direction above the transverse conveyors 8 and / or 17. A plurality of light scanners 57 can also be provided along each cross conveyor 8 in the conveying direction, which, for example, control the operation of the drive motors 31. These light scanners are mounted on motorized or manually controlled, liftable and lowerable light sensor carriers 58. The light scanners 57 have a precisely defined measuring beam length 59 and work with background suppression. The cut surface edge 18 or 19 between the cut surface 22 and the tree edge 43 or 37 can be grasped precisely. The light sensor height is set depending on the wood thickness D. The tree edges 43 or 37 are not detected.

5 shows a schematic sectional view of an embodiment of the cross conveyor for carrying out the alternative method.

The cross conveyor 8 has an upper run 9 and a lower run 10. These two runs extend between the two fixed deflection rollers 63. One of these deflection rollers 63 can be driven. The runs 9, 10 of the cross conveyor, as shown, have a sag so that the operating mode to be described is possible.

The upper run 9 of the cross conveyor 8 is mounted in a guide rail 61. 5 two operating positions of the upper run 9 and its guide rail 61 are shown. The cross conveyor 8 crosses the longitudinal conveyors 5 in areas 11 in which the upper runs of these longitudinal conveyors are deflected downwards in a trough-shaped manner. These troughs enable the upper run 9 and, as will be explained later, the holding rails 62 to be lowered under the upper run of the longitudinal conveyor 5.

To catch up the slack, a compression spring (not shown) can be provided between the upper run 9 and the lower run 10. This compression spring can be supported at one end on the guide rail 61 and the other end can carry a sliding shoe that slides on the lower run 10 of the cross conveyor 8.

The guide rail 61 is carried by two carriers 77, 79. The holding rail 76 is also used by two Carriers 76, 78 worn. All four beams extend approximately vertically downwards.

An angle lever 66, 67 is rotatably mounted on shafts 64, 65. These angle levers have legs 68, 69 extending downward. The legs 68, 69 are connected to one another by means of a push rod 70 in such a way that the movement of one angle lever takes along the other angle lever. The downwardly extending leg 69 of one angle lever 67 is in drive connection with a drive piston 71. The approximately horizontally extending legs 80, 81 of the angle lever 66, 67 have articulation points 72-75 for the Trel 76-81.

As shown, the articulation points 72, 74 of the supports 76, 78 of the holding rail 62 are each closer to the corresponding shaft 64, 65 than the articulation points 73, 75 of the supports 77, 79 for the guide rail 61.

This angle lever link causes at a pivoting angle of the support lever 76, 78 has a smaller stroke of the retaining rail 62 to carry out than the carrier 77, 79 for the guide rail 6. ₁

5 and 6, the angle levers 66, 67 are pivoted such that both the guide rail 61 and the holding rail 62 are in the lowest position. In this position, a wooden element is placed on the longitudinal conveyor 5.

If the lower legs 68, 69 are pivoted to the right, the connecting line of the articulation point 72, 73 and 74, 75 is pivoted upward through an angle. Because of the different distances of these articulation points from the assigned shafts, the assigned supports must inevitably perform a relative movement in addition to the common lifting movement. The parts then reach the position shown in dashed lines in FIG. 6. The upper run 9 of the cross conveyor 8 lies above the upper edge of the holding rail 62, so that a wooden element can be retracted. As soon as this has reached the desired position, the working cylinder 71 executes a first, short stroke, which is sufficient to lower the upper run below the upper edge of the holding rail 62, which can be provided with spikes. At this point, the drive is interrupted and the wooden element is placed on the holding rail. In other places, the conveying to the end position continues. As soon as all the characteristic points on the wooden elements have reached their end position and all upper runs 9 are below the holding rails 62, a further stroke takes place. With this stroke, the end position shown in FIG. 5 is reached, in which a transfer to the longitudinal conveyor was carried out.

To achieve greater strength, as shown, the angle levers 65, 66 were designed as disk-shaped elements.

In this mode of operation, it is only necessary to have two scanners, as shown in FIG. 4, to be arranged one behind the other in the conveying direction of the cross conveyor 8. One of the first scanners then switches the cross conveyor running speed down. The second scanner in the conveying direction are arranged so that they determine the entry of the characteristic points on the wooden element into the end position at this point and the solution of the drive connection between the cross conveyor and. Bring the wooden element. The lower scraper and the holding rails for depositing the wooden element on the longitudinal conveyors 5 are triggered by the last actuated second scanner.

Claims (20)

1. A method for aligning elongated wooden elements in a predetermined manner with respect to at least one reference line, which is determined by at least one processing station, to which these elongated wooden elements are successively fed in the longitudinal direction by means of a longitudinal conveyor, which in turn transversely conveys one of the elongated wooden elements , endless cross conveyor is fed, in the conveying area of which at least one optical scanning station for determining parameters which are characteristic of the elongated wooden elements and characterize their spatial arrangement is seen, and which can give a control representing these parameters signals for controlling position adjusting devices for the elongated wooden elements, characterized in that
the elongated wooden element (1) is brought into a longitudinal conveying position at a distance above endless longitudinal conveyors (5) by means of the transverse conveyors (8), so that the speed and / or conveying direction of the individual transverse conveyors (8) are controlled by the controller (15) that the elongated wooden element (1) is aligned in this longitudinal conveying position in the predetermined manner with respect to the reference line (16), and that after the elongated wooden element (1) has reached the longitudinal conveying position aligned in this way, the cross conveyor (8) is stopped and thus lowered be that the elongated wooden element (1) is placed on the longitudinal conveyor (5). 2. Method for aligning elongated wooden elements in a predetermined manner with respect to at least one reference line, which is determined by at least one processing station, to which these elongated wooden elements are successively fed in the longitudinal direction by means of a longitudinal conveyor, which in turn transports one, the elongated wooden elements, in the transverse direction Endless cross conveyor is loaded, in the conveying area of which at least one optical scanning station is provided for the determination of parameters which are characteristic of the elongated wooden elements and whose spatial arrangement characterizes them, and which emits the corresponding signals which effect and align,
characterized in that
the elongated wooden element (1) is brought into a longitudinal conveying position at a distance above endless longitudinal conveyors (5) by means of the transverse conveyors (8), so that, when the foremost parameter in the direction of travel is passed at the first scanning station of the relevant transverse conveyor (8), the running speed of all Cross conveyor is reduced, and that when the second scanning station is reached, the predetermined end position is reached and the drive connection of the cross conveyor in question (8) to the elongated wooden element (1) is interrupted while simultaneously placing it on an intermediate carrier adjacent to this cross conveyor (8), and after the last drive interruption, the intermediate beams are simultaneously lowered so that the elongated wooden element (1) is placed on the longitudinal conveyor (5). 3. The method according to claim 1, characterized in that
the optical scanning stations (32) determine the actual positions of certain parameters on the elongated wooden elements (1) at several points transversely to the conveying direction of the cross conveyors (8), compare them with the target positions specified in the control (15) with respect to the reference line (16) and that the results are used to control the cross conveyor (8). 4. The method according to claim 1 or 3, characterized in that
the optical scanning stations (32) determine the entry of predetermined locations of the wooden elements (1), which are distributed transversely to the conveying direction, into the predetermined end position, which is given by the desired alignment with respect to the reference line (16), and that the control (15 ) Corresponding command signals for infeed control of the elongated wooden elements (l) in the predetermined orientation position relative to the reference line (16) for the controlled cross conveyor (8) are derived. 5. The method according to any one of claims 1 to 4, characterized in that
if more than two cross conveyors (8) are used, only the two outer ends of the conveyed wooden elements (1), which are the first ends, are controlled by the controller (15) and that the intermediate ones remain inactive. 6. The method according to any one of claims 1, 3 to 5. characterized in that
the lowering of the cross conveyor (8) is carried out in several stages. 7. The method according to any one of claims 1, 3 to 6, characterized in that
the cross conveyors (8) are loaded by means of an upstream, second cross conveyor (17), and that the optical scanning of the elongated wooden elements (1) on the upstream cross conveyor (17) and / or on the cross conveyors (8) leading to the longitudinal conveyors (5) is carried out. 8. The method according to claim 2, characterized in that
the upper run (9) of a cross conveyor (8) is moved up and down in a controlled manner between a plane which lies above an associated intermediate beam which extends along the upper run and a plane which lies below this intermediate beam. 9. The method according to claim 2 or 8, d3 characterized in that
the upper run (9) of the cross conveyor (8) and the associated intermediate carrier are moved up and down together in a controlled manner in the region (11) of trough-shaped deflection points (24) of the longitudinal conveyor (5). 10. Device for performing the method according to one of claims 1 to 9, characterized in that
at least two parallel, endless longitudinal conveyors (5) each in the upper run (6) have at least two spaced apart groups (12) of areas (11) arranged in a line perpendicular to the conveying direction, in which they upper run (6) in downward, trough-shaped guides (24) and that extendable through the areas (11) and lowerable cross conveyor (8). 11. The device according to claim 10, characterized in that
the downward, trough-shaped guides (24) are slide guides made of a friction-resistant and self-lubricating plastic material, the inlets and outlets (25, 26) of which lie in one plane. 12. The device according to one of claims 10 or 11, characterized in that
the endless longitudinal conveyors (5) have chain conveyors. 13. The device according to one of claims 10 to 12, characterized in that
between the discharge end of the longitudinal conveyor (5) and the entry end of the processing station (3, 4) a drivable hold-down device (33) for the langge stretched wooden element (1) is arranged. 14. Device according to one of claims 10 to 13, characterized in that
each cross conveyor (8) is a chain conveyor. 15. The device according to one of claims 10 to 14, characterized in that
in the scanning stations (32, 32 '), height-adjustable light scanners (27) are arranged, which have a precisely defined, vertical measuring beam length (59) with background suppression and precisely detect the cutting surface edge (18, 19) between the cutting surface (22) and the tree edge. 16. Device according to one of claims 10 to 15 for performing the method according to claim 2; 8, 9, characterized in that
the upper run (9) of the cross conveyor (8) is guided in a guide rail (61), along which a holding rail (62) extends as an intermediate carrier, so that the guide rail (61) is opposite the holding rail (62) can be raised and lowered and that the holding rail (62) and guide rail (61) can be raised and lowered together. 17. The apparatus according to claim 16, characterized in that
An angle lever (66, 67) is mounted on each of two parallel shafts (64, 65), the downwardly extending legs (68, 69) of which are connected by means of a hinged push rod that one of these legs (69) is connected to a drive piston ( 71) that the approximately horizontally extending legs (80, 81) of the angle levers (66, 67) each have two articulation points (72 - 75) for carriers (76 - 79) for the holding rail (62) and the guide rail (61 ) and that the articulation points (72, 74) of the carriers (76, 78) of the holding rail (62) have a smaller distance from the shaft (64, 65) than the articulation points (73, 75) of the carriers (77, 78 ) the guide rail. 18. The apparatus according to claim 16 or 17, characterized in that
the deflection rollers (63) of the cross conveyor (8) are fixed in place and are driven by a single drive motor. 19. Device according to one of claims 16 to 18, characterized in that
the upper edges of the holding rails (62) carry spikes. 20. Device according to one of claims 16 - 19, characterized in that
the upper runs (9, 10) of the cross conveyor (8) are spread out by spring force.

Images