FI73832C - A method for measuring multiple diameter values for an elongated object, e.g. a wooden warehouse and apparatus for carrying out the process there - Google Patents

Description

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A method for measuring a plurality of diameter values of an elongate object, e.g. a timber log, and an apparatus for carrying out this method Förfarande för mätning av flera diametervärden för et längsträckt föremäl, t.ex. en travarustock och anord-Ning för genomförande av förfarandet

The invention relates to a method for measuring a plurality of diameter values of an elongate object, e.g. a timber log, which is continuously conveyed by a conveyor with two parallel slide rails and which, in different directions of measurement, each emit their beam, which may pass past the break point of the guide rails. The invention further relates to a device suitable for carrying out the method.

A number of non-contact electro-optical measuring devices for measuring the diameter of elongate objects are already known. SE patent publication 210.166 describes one such measuring device of the type mentioned in the preamble of the 15 main claims. U.S. Pat. No. 3,806,255 describes a method and a plurality of devices for measuring curvature, starting from values obtained by measuring the diameter in several measuring planes along two mutually inclined measuring directions. In both cases, the obtained measurement values are fed as electrical signals to a computer, where the results are calculated and assigned in a manner known from computer technology.

German Offenlegungsschrift 25 55 975 describes an apparatus for measuring the diameter of frames with two longitudinal projectors which are completely separated at the measuring point by an opening through which light from a light source can pass to the measuring device. When moving from one device to another, there is a risk that the log will cause an uncontrolled pivoting movement, so that the curvature cannot be determined.

U.S. Pat. No. 3,724,958 describes an apparatus for measuring the diameter of frames which are conveyed by a conveyor chain and which are raised and rotated about a longitudinal axis at the feed point by means of traction rollers. In this way, too, the curvature cannot be determined.

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The invention relates to a new method and device for taking measurement values to be entered into a computer. As a result, depending on the programming of the computer, an indication of the diameter and / or curvature is obtained, which, however, is not in principle within the scope of the present invention. The invention is still explained in more detail on the basis of the curvature measurement, since this measurement places stricter requirements on the measuring device so that the diameter can also be measured automatically with a system enabling the curvature measurement.

The object of the invention is e.g. provide a device suitable for both of these purposes. In this case, a measurement method is applied in which the light rays are caused to pass both end points of the diameter of the object. This method is more accurate than the method based on measuring the light reflected by an object, which is used, for example, in the device according to Figures 2 and 3 of said US patent publication.

The task is solved as set out in the appended claims.

The invention will be explained in more detail with the aid of the accompanying drawings, which illustrate some exemplary embodiments. Figures 1 and 2 schematically show the measurement of the curvature of a timber log, Figures 3 and 4 schematically show the principle of operation of the diameter measuring device according to said 5E patent publication 210.166, Figure 5 diameter measuring device, Fig. 7 is a schematic front view of a first embodiment of a measuring device according to the invention, Fig. 8 is a top view of a part of a first embodiment of a conveyor, Fig. 9 is a side view of a gripper according to the invention, Fig. 10 is a schematic top view of a second embodiment of a conveyor. schematically shows a front view of another embodiment of the measuring device, and Fig. 12 schematically shows a side view of a third embodiment of the conveyor.

Figures 1 and 2 show a log 20 having a front end surface 20A and a rear end surface 20B, the curvature of which can be determined by arrow height or P2.

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Both arrow heights refer to the distance between the centers of both end faces connecting the straight line D, i.e. the ideal center line, and the curved line C passing through the centers of all cross-sections of the log, i.e. 5 the actual center line. The arrow height is measured at a point D hyphen half the length of the case, while the arrow height is measured at point D ^, where the height is the largest. In this case, it should be noted that the transported log 20 can be curved in an arbitrary direction 10, so that e.g. Apparently, however, this arrow height can always be calculated according to Fig. 2 by summing the two arrow height projections P 'and P "in two mutually inclined and suitably but not necessarily perpendicular projection planes M 1 and M 2. In Fig. 2 C' and C" and the projections of the connecting line D 'and D' and D 'on both projection planes.

According to Fig. 3, a diameter measuring device of the type mentioned in SE 210.166 operates as follows: an elongate light source 1 illuminates a parabola mirror 2, the focal point of which is a mirror 3 rotating about an axis of rotation AA and oblique to this axis. the boundary rays 25 'are B' and B ", are thus reflected from the mirror 2 and are focused on a small mirror 3 which reflects the light beam: to a photosensitive sensor, e.g. a photocell 4 fitted: for the extension of the rotational cassette line AA. · The pulse sensor used in the small mirror 3 is electrically connected to a computer 16, where the diameter is calculated in a manner known per se from computer technology on the basis of the shaded, spaced and spaced area of the object in the measuring position. in said patent publication 210.1 66. The measurement can also be explained by measuring two distances H ^, H £ starting from the selected reference plane G, where H ^ represents the distance between the reference plane G and and the transition point between shadow and light, while denotes the distance between the reference plane £ and light 4 73832 and shadow. the distance between the transition point. By performing a subtraction ^ £ ”^ 1, the diameter of the object at the measuring point and in a direction parallel to the light source 1 and the axis of rotation A-A, i. towards -5 in a straight line against the direction of attack. Continuing the calculation by summing half the result of the subtraction to the distance H £ (or subtracting from the distance H ^), the position of the center point with respect to the reference plane £ is obtained. These calculations and their storage and interpretation take place in a known manner in the computer 16. The invention relates to a method for taking the results entered in this computer.

Since the cross-section of timber beams is rarely regularly circular, the described diameter measurement according to Figure A is suitably made in two (sometimes up to three) 15 different measurement directions. For this purpose, according to Fig. 4, two parabolic mirrors 2a, 2b and two elongate light sources 1a and 1b are arranged side by side. The diameter is thus measured in two measurement directions, which are represented, for example, by the boundary radii B '^, B "^ and B'2, B" ^ of the two light beam beams.

20 The measured values of the diameter are then obtained in directions perpendicular to the measuring directions. The measured log 20 is then conveyed in the longitudinal direction by a conveyor, which has, for example, a keratin track, i.e. a floating wood conveyor track 40, on which the log rests on low grippers 41. The chain 42 pulls these grippers 25 between two side-mounted longitudinal slide or guide rails 43, 44. It can be seen from Figure 4 that the conveyor prevents the diameter measurement because it obscures substantial parts of both light beams. When measuring the diameter, the conveyor 40 has hitherto been divided at the measuring point so that, according to Fig. 5, a gap E is provided for the free passage of the light beam beams B1 and B2 in the measuring plane N (in the plane of the drawing in Fig. 4). Fig. 5 schematically shows two conveyors (kerat track) 40a, 40b and a measured log 20 just passing the gap E.

Figure 6 shows a complete diameter measuring apparatus operating according to the principle explained on the basis of Figures 4 and 5. The parabolic mirrors 2a, 2b with their associated accessories are each mounted in their housings 32a, 32b and both housings are attached to adjacent branches of a square-angled frame 11,573,832. The light sources 1a, 1b are arranged in both other branches 31a, 31b of the frame 33. The first transport path 40a to transfer the logs in the direction of the arrow £ described the diameter of the measuring instruments 5 to 30 and an entirely separate second transport path 40b further move logs from this measurement device 30. The operator reads the display unit U 16 18 calculated by the computer.

As it moves from the second conveyor 40a to the second conveyor 40b, the log 20 can apparently rotate arbitrarily around the centerline, which in no way affects the diameter measurement because the diameter is measured along two randomly selected inclined measurement directions. However, such a rotational movement te-13 makes the measurement of curvature impossible, since this measurement requires that the direction £ (Fig. 1) be constant, although it can, of course, be located in an arbitrary plane.

According to the invention, the problem is solved as shown in Figures 7 to 12. The low grippers 41 of Figs. 4 and 6 are replaced by higher grippers 51 according to Figs. 7 and 11, which also allow the light of the light beam beams B1, B2 to pass under the log, either between the log and the transport track according to Fig. 11 or in the middle of the transport track according to Fig. 7. through the free space 45 between the two slides 43, 44, so that nothing is forced to divide the conveying path in the longitudinal direction. The transport path can be made undivided, thus avoiding the rotation of the log during the measurement. For most of the length of the log 20, in fact along the entire length of the log, except for those short intervals where the log 20 rests on different grippers 51, a free space Y (Figures 11, 12) of height H is made to form the lower part of the log 20. and between the fixed part of the conveyor, i.e. the upper edges 43a, 44a of the rails 43, 44. The passage of light under the log 20 is further facilitated by dividing each slide rail 43, 44 instead of the measuring plane N (i.e. the drawing plane of Figs. 7 or 11), the grippers 51 according to Fig. 9 being made upside down in the shape of an inverted T so as to have a long base 51a the length L of the base exceeds the width j <of the breakpoints F ^. The chain 42 thus continues undivided past and through the breakpoints. The log 20 cannot rotate because the guide and slide rails 43, 44 always guide each gripper 51 at least along a part of its base 51a and the gripper thus continuously supports the log 20. The effective height Z 1 of the support part 51b, i.e. the height to the lowest point 51c of the support surface, protrudes past the upper edges 43a, 44a of the gap H (Fig. 7).

Both of the measuring means 10 couples Ia, Ib and 2a, 2b may be of Figure 7, also arranged staggered to each other in any way of the arrow II Sunnah (Figure 6). In this case, according to Fig. 10, the break points N1, Ng are also staggered to a corresponding extent. In both planes, the free passage of the light beam under the log 20 is only required on one side of the conveyor 40, as can also be clearly seen in Figure 7.

Fig. 10 further shows a sensor 17 for detecting the movement of the conveyor 40 and thus the movement of the log, which is connected to a computer 16. This sensor exists 20 in all embodiments, although for the sake of clarity it is only shown in Fig. 10.

Hitherto, it has been assumed that the pairs of measuring elements 1a, 2a and Ib, 2b are inclined with respect to the vertical as shown in Figures 4, 6 and 7, so that each measuring direction forms an acute angle «C (0 ° WC <90 °) vertically \ / with (Figure 7). According to Fig. 11, the pairs of measuring elements 1a, 2a and Ib, 2b can be arranged so that their measuring directions are vertical and horizontal, using broken points 30 arranged as shown in Fig. 8 (this figure can therefore be related to both Fig. 7 and Fig. 11 and in principle 12 to display).

The device shown in Fig. 11 can still be suitably varied as shown in Fig. 12. The purpose of this embodiment according to Fig. 12 35 is to prevent falling waste from contaminating the light source Ib below the conveyor 40. The entire measurement level N "(drawing plane of Figure 11) may tilt angle / 3 in the feeding direction (the arrow direction), the protective cap 19 suitably placed in the light source of IL 73832 7 Ib on tea ,. For the same purpose, the measurement, i.e. of course, can be set at an angle to the direction of travel. The edges of the breakpoints F1 "are also suitably inclined. The computer is programmed to compensate for this inclination with respect to the measured value of the vertical diameter (no compensation is required horizontally), so this value is multiplied by cos / 3. It should be noted that in all embodiments the light beams pass through two breakpoints of the conveyor, either so that each light beam passes through one breakpoint (Figures 7, 10) or the other light beam passes through two breakpoints (Figure 11), while the other light beam does not pass through any breakpoint.

The described embodiments can be varied in many ways within the scope of the invention. Conveyors other than kerat tracks and other diameter measuring devices than those described in said SE patent publication 210.166 may be used. Thus, the diameter measuring device of Figure 4 of said U.S. Patent No. 3,806,253 may be used if a plurality of in-line light emitting diodes emits light received by a corresponding number of in-line photoelectric cells. In this case, the wide light beams according to Fig. 4, B? Are replaced by several narrow light beams from several separate small light sources, whereby each such narrow light beam can be considered as a sub-beam in a wide light beam comprising all small light sources.

The measurement directions can form an angle other than 90 ° with each other, as long as the vector summation of the corresponding projections (according to Figure 2) can give a reliable result. The measurement 30 can be performed in two directions in several directions, e.g. by combining the measurement methods shown in Figures 7 and 8 or 10 with the measurement methods shown in Figures 11 and 8, which are placed very close to each other along the conveyor 40.

In all embodiments, the number and location of the measurement along the length of the log 20 is determined in a known manner by programming the computer 16 and the signals provided by the sensor 17.

Claims (9)

A method for measuring a plurality of diameters of an elongate object, e.g. a timber log, which is continuously conveyed by a conveyor (49) having two parallel slide rails (43, 44) and a plurality of grippers 5 moved along a conveyor chain (42) and conveys past the log an electro-optical measuring device (30) with at least two light sources (1a, 1b) which, in different measuring directions, each emit their beam (B'^ -B "^ - B '2" ^ "2)» j ° t * <a can pass through the break point of the guide rails F^, F2, F'^, F '2 legally ^"l^ °hi> characterized in that the log (20) is passed past the measuring device (30) in a safe non-rotatable position so that the grippers (31) always guides the guide rails past the break point at part of its base (31a) while the grippers convey the log so high that its lower edge is at such a distance (H) from the upper edge (43a, 44a) of the guide rails that the light of the measuring device can pass between the lower edges and possible past the transport chain, which continuously bypasses the breakpoints (F ^, F ^, F '^, F' 2, ^ "l ^ * A method according to claim 1, characterized in that the beam beams are each sent to different measurement planes (N 1, N 2) which are staggered in the feed direction (S) of the log so that the parts of the different beam beams each pass through their cut-off points in the same ratio. -25 in tea staggered as measurement levels. Method according to Claim 1, characterized in that the beam is transmitted in measuring directions which are at the same measuring plane and which are inclined with respect to the conveying direction of the log. Method according to Claims 1 to 3, characterized in that one of the light beams is emitted in a substantially horizontal measuring direction and in such a way that the part in question the beam is made to pass under the lower edge of the log. Apparatus for carrying out the method according to claims 1 to 4, wherein the apparatus comprises at least one electro-9 73832 optic non-contact measuring device (3) with at least two light sources (1a, 1b) adapted to emit each of its beam (Θ '^ - Β "^), in different dimensional directions for receiving a photosensitive sig-3 signal sensor (4) and adapted to provide output signals which are input to a computer (16), characterized in that the device comprises a conveyor (49) with a fixed part (43, 44) and a moving part (42) , 51), in which the fixed part is arranged with two breaking points (F ^, F ^, F '^ * F ^, ^ "1 · * so that a part of the light beam coming from at least one measuring device passes through them, and the moving part is arranged to pass past the breaking points and at the same time to carry the elongate object (20) in the raised transport position 15 relative to the fixed part, and at least two of said measuring devices are located in such an inventive way; in a position that their measurement directions intersect each other, and parts of the developed light passing through two of said break-point and / or a free intermediate space (Y) of the object float 20 due to a transport position Hercules-Beta is born in the upper parts of the object underside and the transport device fixed part ( 43a, 44a). Device according to claim 5, characterized in that the transport device comprises a keratin-25 track with two longitudinal guide and slide rails (43, 44) and a continuous zipper (42) and a plurality of grippers (51) fitted to move between the rails, as a joint in said chain and in the form of an inverted T-letter, the base (51a) of which is longer than the width (K) of the breaks 30 fitted to the rails and the vertical support part (51b) projecting at its effective height (Z) 44a) pass. Device according to Claim 5 or 6, characterized in that the breakpoints are arranged directly in alignment and the two measuring devices have a common measuring plane (N) (Fig. 8). Device according to Claim 5 or 6, characterized in that the breakpoints are arranged in stages in the feed direction (5) of the conveyor, that each measuring device has its own separate measuring level (N 1, N 2) and that both measuring levels are similar staggered with each other (Fig. 10). Device according to Claim 7, characterized in that the two measuring devices are arranged so as to have a measuring plane (Ν ') which is inclined with respect to the conveying direction of the conveyor, the breaking points (F "^) suitably having similarly inclined edges ( Fig. 12) .n 73832