FI56900C - FOERFARANDE OCH ANORDNING FOER BESTAEMNING AV EN VANKANTAD BRAEDAS LAEGE OCH FORM - Google Patents

Description

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FINLAND —FINLAND (21) P »t * nttlluk * mut-P» t ** ai »« öki «lfi | 770UU8 (22) HakmtopMv »—AmdfcnlnpdH 11.02.77 (23) Alkupllvl — GIW | t» * ed * f 11.02.77 (41) Has become public - Victims offantHf 12.08.78

Patent · and jockey board · (44) Nthuviksip ^ j. kuugulk ^ and p ** .-

Patant- och raglatarstyralaan 'Amekan utiagd och utijkrMtwi pubUcund 31.12.79 (32) (33) (31) Requested modification · —Boflrd prlorlut (71) A. Ahlström Osakeyhtiö, 29600 Noormarkku, Finland-Finland (FI) (72) Heikki Juhani Meriläinen, Karhula, Suomi-Finland (FI) (5 * 0 Method and apparatus for determining the position and shape of a non-edged board - Förfarande och anordning för bestämning av en vantantad brädas läge och form When edging sideboards automatically or semi-automatically, the narrower edge of the board must be In general, the turning of the board in the right direction is performed manually or mechanically by means of a device, and to automate this step, a device has been developed in Finnish Patent Application No. 1815/73, which uses electromechanical sensors to determine an incorrectly facing board. it only measures the leading edge of the board, making the determination of the position of the sawn side board alone uncertain.

The present invention relates to a method and apparatus by which the position and shape of a board can be determined taking into account the front and rear edges of the board as it passes laterally at a constant speed past the sensor. The method according to the invention is characterized in that the board is made to pass along a support plane through a converging light beam whose convergence point is at or near the support plane of the boards, and that the shading or illumination speed of the light beam is measured as the board cuts the light beam * 2 569

Depending on the position and shape of the board, the cutting pattern varies, and by measuring the rate of change of luminous flux, luminance or light power opto-electronically, the position of the board can be deduced. The convergence of the light beam can be done by means of a transmitter or a receiver.

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The device according to the invention is characterized in that it comprises a support plane along which the board moves laterally, a light source arranged on one side of the support plane, emitting light rays forming a converging light beam through which the board passes and whose convergence point is on or near the support plane. an adapted photosensitive member for measuring the shading and illumination rate of the light beam as the board cuts the light beam. With the device according to the invention, the determination of the position and shape of the board can be performed regardless of the shape of the edges of the board. The device is also capable of recognizing a fully edged board.

The invention will now be described in more detail with reference to the accompanying drawings, in which Fig. 1 schematically shows the main parts of an embodiment of a device according to the invention, Fig. 2-5 shows four alternative solutions, Fig. 6 shows three different examples illustrating the principle of operation of the device, Fig. 7 Fig. 8 shows four different board shapes and the changes in electric current caused by them in the light detector, Fig. 9 shows an application example of the device and Fig. 10 illustrates its operation when turning the board, Fig. 11 shows another application example.

In Fig. 1, a light source denoted by reference numeral 1 emits a converging light beam 2, the converging point 3 of which is in the support plane 5 «of the board 4, along which the board slides laterally. Below the board is a collecting lens 6, with which the light beam is collected on a light-sensitive electronic component 7 »whose transmitted electric current changes according to the amount of light entering its surface. Examples are light emitting diodes and phototransistors. In the embodiment shown in Figure 2, the converging light beam is provided by means of a lamp 8 and a collecting mirror 9. The photosensitive member 7 is located immediately behind the suppression point 3 of the light beam 2.

3 56900

Figure 3 shows a lamp 8 and a mirror 10 above the board, from which the light rays reflect in all directions · At the edges of the opening 11 in the support plane 5, the light rays entering the photosensitive member 7 are delimited.

In Fig. 4, the light beam coming to the photosensitive member 7 is assembled by means of the line 6.

Figure 5 shows a converging mirror 12, which reflects a converging light beam on the surface of the photosensitive member.

Figure 6 shows three typical cutting methods of the front edge of the board · 6 A shows the underside upward board 4, where the cutting takes place close to the convergence point 3 of the light beam 2 and is fast · 6 B shows the opposite case, where the cutting pattern 13 is a larger circle * 6 C shows the full edge · In this case, half of the light beam is cut slowly And half is fast · The light transistor 13 is used as a light-sensitive component in the measurement plot shown in Fig. 7. · to contact 18 via rectifier 19 · Positive pulses Conducted via rectifier 20 to the cover of thyristor 21. The operating time of the timer circuit is determined by means of resistor 22 and capacitor 23. And the output is connected to the base of transistor 24. · A supply voltage, for example 12 Y, is applied to point 25.

The principle of operation of the measuring column is as follows

As the front edge of the board darkens, the voltage of the light beam drops at point 26 · If the change is slow, the capacitor 16 is discharged through the front support 15. The rapid change causes a negative pulse at point 18 »f. Whereby the actuator pole 17 pulls the transistor Zk to the conductive state to operate. The trailing edge of the board causes a rising voltage to point 26, and if the rise is fast enough, a positive pulse ignites at point 18, which pulls the thyristor 21 to the conducting state. If both the leading and trailing edge pulses are fast, the control voltage for the actuators is obtained from point 27 · Transistor 24 is reset when the timer circuit 17 expires, whereby the thyristor 21 and the output point Z ^ are also reset · The operating time of timer circuit 17 can be set to seconds, for example. the derivative currents of the board type at point 26 of the measuring circuit. In the case of 8 A, both edges give a rapid change, whereby a control voltage is generated at point 27. In case 8B, both edges are slow, leaving both transistor 24 and thyristor 21 non-conductive. In the case of 8 B, the leading edge is fully * 56900 edged, so that half of the light power goes out quickly and the transistor becomes conductive. The trailing edge gives a slowly rising current, in which case the thyristor does not receive a control pulse, and no voltage is generated at point 27. In case 8 D both edges give a fast pulse And from point 27 a voltage is obtained.

The limit speed of the derivation circuit at which the pulses still arrive can be changed with an adjustable resistor 15 · At high levels the resistance of the derivation steepness decreases and vice versa.

When looking at sideboards sawn from supports, it is sufficient to measure the other edge.

In pedal transport of side boards to the edging, there are several steps for which the measurement would be suitable. Probably the best is the kirama stage, where turning the boards is simple. The apparatus may be, for example, archaic in Figures 9 and 10. The board is transported along surface 5 by my light Ismi s imen 28 under the light source 1. The coil of the spring-return solenoid valve 29 is connected to point 27 of the measuring column (Fig. 7) and to the ground. The valve controls the working cylinder 30, which drives the jaw bar 31. As the jaw passes the sensor, depending on the shape, a voltage is generated at point 27 and the valve changes position until the voltage at point 27 drops. The valve bar also changes position with the valve. If the underside is desired upwards, pull the magnetic coil to the position (a) of the age bar when it is operating and the right-hand board can pass. The upside-down board pivots on the chest of drawers 32 (Fig. 10) with the age bar in position (b). If the lower edges are to be lowered, the operation of the working cylinder is reversed. (s * \

The method according to the invention can also be used for measuring the width of a board, for example in determining the cutting points of edged boards by placing light detectors 28 in a row according to Fig. 11. In this case, the board is turned upside down in advance.

Claims (8)

A method for determining the position And shape of a board traveling laterally at a constant speed, characterized in that the board {k) is passed along a support plane (5) through a converging light beam (2), the convergence point (3) of which is at or near the support plane of the boards. - or the illumination rate is measured when the board cuts a beam of light. Device for carrying out the method according to claim 1, characterized in that it comprises a support plane (5) »along which the board (* f) moves laterally, a light beam (1) arranged on one side of the support plane, emitting light rays, forming a converging light beam (2) , Through which the board is made to pass' And Whether the point of convergence (3) is at or near the support plane, and the photosensitive members (7) fitted to the other side of the support plane ».The measurement of the light beam shading and illumination rate is measured when the board cuts the light beam. Device according to Claim 2, characterized in that the convergence of the light beam (2) is effected by collecting the light rays emanating from the light source (1) by means of a mirror (9). Device according to Claim 2, characterized in that the convergence of the light beam (2) is effected by means of an opening (II) in the support plane (3). Device according to Claim 3 or k, characterized in that the photosensitive element (7) is arranged immediately behind the convergence point (3) of the light beam (2). Claims 56900 Device according to one of Claims 2 to 3, characterized in that the light rays of the light beam (2) are collected on the light-sensitive element (7) by means of a mirror (12) or a lens (6). Device according to one of Claims 2 to 6, characterized in that a measuring circuit (Ui, 13 and 16) deriving the rate of shading and illumination is connected to the photosensitive element (7). 6 56900 Device according to Claim 7, characterized in that the board (saatu) is obtained from a derivative measuring circuit (1 * 1, 15 and 16). the position indicating pulse is used to control the device (31) for turning the board.