FI69263C - ANORDNING FOER KONTINUERLIG CENTRERING AV EN VIRKESBIT - Google Patents

Description

69263

Device for continuous centering of a piece of wood

The present invention relates to an apparatus for continuously centering a piece of wood, which piece of wood is fed to a woodworking machine by means of at least one feed roller with rectilinear sheath surfaces and which is then displaced laterally relative to the center plane of two machine tools by lateral control.

One such device is described, for example, in Swedish Patent Publication 334,460, in which the guide rollers comprise at least a pair of upper and lower feed rollers e-10 of the saw machine and each guide roller arranged on its own side, each rotating about its vertical axis The guide rollers press against the piece of wood due to the fact that they are affected by a bifurcated rope arrangement measuring the weight of the load-15, which tends to move the support arms towards each other. However, the rope arrangement cannot guarantee forced steering because the other leg may loosen.

It is an object of the present invention to provide an improved device of the type mentioned at the outset which is simpler and more space-saving and guarantees reliable lateral control in the lateral direction. As a result, the load on the saw blade is kept to a minimum. The problem is solved as it appears from the appended claims. The device according to the invention is intended in particular for e.g. for core wood sawing, which mer-25 specifies that the saw mark or marks also in curved pieces of wood are at the core (= center) of the piece of wood or parallel to it. In this way, a wooden log (= a piece of wood with two parallel planes) is used better, because otherwise it would be straightened over the curved part. If the sawing mark or marks 30 then follow the direction of the fibers in the log without greater than the direction of curvature, i.e. evenly curved in one direction, the resulting boards and planks, which are essentially curved in the same way as the core was curved, will self-correct in drying. feeding 5 straight lines through a circular saw, straight boards and planks are obtained, but there is a great danger that these will become curved during drying.

Thus, in the case of core wood sawing, at the time of feeding the log, each log cross-section must be so oriented with respect to the saw-10 chopper that the center in the point-core-just-entered cross-section is located mainly in the center plane of the saw (vertical plane of symmetry). For the best lateral control of the log, the "turning point" of the lateral movement of the log should be located as close as possible to the saw teeth. The load on the saw blade is also the lowest.

In the centering, it must also be noted that the diameter in each successive cross-section of the log changes more or less continuously, as each frame narrows from the top to the base.

The invention will be explained in more detail by means of three application examples of Figures 1, 2, 3 of the accompanying drawings, which show a front view (from the inlet side) of three different circumferential sawing machines equipped with a device according to the invention. Reciprocating saw 10 is always the directions of the double arrow 25 is instantly increased to a firm commitment is calculated and the boom 19, two of the saw blade 11 and the gear 19a is used by the lower feed roll 19a. A pair of output rollers can be arranged on a non-shown output side of the machine in a manner known per se.

A horizontal shaft 17, 30 rotatably mounted on the boom 19 is rotated by a sprocket 22 and a chain 21. Two conical guide rollers 12a, 12b are displaceably arranged on the shaft 17 in its longitudinal direction, the narrower ends of which face each other so that together they form a diabo roller. Between the guide rollers 12a, 12b, there is a cylindrical roller 20 on the shaft 17. The guide rollers 12a, 12b are non-rotatably connected to the shaft 17 by an elongate groove 17a and not shown in its groove on its inner circumference. The cylindrical roller 20 is non-rotatably and non-displaceably connected to the shaft 17, for example by a fastening bolt 20 ', and is located in the central plane S of the saw machine.

According to Fig. 1, two racks 24a, 24b are each arranged to be moved above the shaft 17 on its horizontal guide 23a, 23b. In the vertical space A between the two racks 24a, 24b, a freely rotating gear 25 is arranged, which engages the tooth rows of both racks. Attached to each of the racks 24a, 24b at their opposite ends are a conveyor 26a, 26b at one end. With its second fork-shaped top, the annular groove 29 of the conveyor 26a, 26b engages in the outwardly projecting hub collars 12a ', 12b' of the guide rollers 12a, 12b.

A double-acting hydraulic unit comprising a cylinder 15a and a piston 15b with a piston rod 15b 'is attached to a boom 15 19, the free end of the piston rod 15b * being connected to a rack 24a.

Electrical contact member 16 is adapted to provide a start signal when the boom 19 reaches a certain direction of the arrow P elevation or more. For the sake of clarity, the contact device is shown in the drawing in the disconnected position, although the saw machine is otherwise shown in the operating mode.

The device operates as follows: during the sawing cycle, the feed roller 19 and the horizontal shaft 17 rotate continuously. The guide rollers 12a, 12b are located furthest apart in the starting position. When the piece of wood 25 enters the feed part of the saw machine 10, a cylindrical roller 20 rises, as a result of which the shaft 17 and the boom 19 also pass, which then bypasses the above-mentioned predetermined height position, and the contact device 16 closes (not shown). The pressure fluid flows into the cylinder 15a via the right-hand supply line 30 28 and thus triggers the coordinated movement of the guide rollers 12a, 12b inwards, because the gear 25 then forcibly transfers the inward movement to the second rack 24b as well. When both guide rollers 12a, 12b come into contact with the piece of wood 30, the center line C in its respective cross-section is located substantially in the vertical plane of symmetry S of the saw. Depending on how the width of the piece of wood changes during feeding, the guide rollers 12a, 12b move in the same direction. “69263 or outward. The compressive force of the guide rollers on the piece of wood can be adjusted by adjusting the pressure in the cylinder 15a. In this way, it is also possible to adjust how strongly the center line C of the piece of wood is forced into the plane of symmetry S, 5 of the sawing machine, i.e. how to follow the steep bends of a piece of wood. When the lateral force of the piece of wood 30 becomes too great, one of the guide rollers 12a, 12b moves to the side, thereby overcoming the compressive force of the cylinder 15a, which is preset to the desired value.

When the piece of wood 30 leaves the feed section of the saw machine 10, the boom 19 lowers, the contact device 16 opens, the pressure fluid flows into the cylinder 15a via the left feed line 27, the guide rollers 12a, 12b move as far apart as possible and the device is ready to receive a new piece of wood. the explained section is repeated.

At all times, the guide rollers 12a, 12b and possibly also the cylindrical roller 20 acting as a sensor have acted like an upper feed roller, which is thus completely replaced by the rollers. This allows the guide rollers 12a, 12b to be located as close to the saw blade 1 as is generally movable, while in known constructions they must be placed in front of the feed rollers. It is clear that the racks 24a, 24b can also be moved by rotating the gear 25 in one direction or another.

The device according to Figure 2 in the sawing machine 10 'differs from the device according to Figure 1 in that the gear 25' is mounted by means of a second double-acting cylinder-piston assembly 35.

When the first unit 15a, 15b causes a change in the distance between the guide rollers 12a, 12b, i.e. that they move in opposite directions, the second unit 35 provides a lateral movement of both guide rollers 12a, 12b in the same direction and the same distance. The second unit 35 is fed from a pressure fluid source (not shown) in a known manner, which is outside the scope of the present invention 35, and which signals are obtained and developed in the calculation unit U, starting from, for example, measuring a machined piece of wood. During operation, both aggregates 15a, 15b and 35 operate simultaneously and the corresponding movements of the guide rollers are combined.

In the sawing machine 10 "of Fig. 3, the conveyors 26a, 26b are driven by a screw spindle 34 with two threads with opposite pitches. Corresponding nut threads are arranged in the transducers 26a, 25b. The screw spindle 34 is driven by an electric motor 32 via a gear and an adjustable slider 33. device in the same way as the device according to Figure 1. It is clear that the invention can also be used in connection with woodworking machines other than sawing machines, for example in connection with thinners or the like.

Claims (10)

6 69263 A device for continuously centering a piece of wood, which piece of wood is fed to a woodworking machine (10) by means of at least one feed roller (18) with straight casing surfaces, which is then laterally displaced by a rotating side guide member (12a) 12 relative to the center plane (S) of the machine tool. , characterized in that the side guide members consist of a pair of cooperating guide rollers having conical, tapered surfaces facing each other and axially displaceably arranged on the common horizontal shaft (17) to rotate about it and which are motor-driven rigid mechanical guide systems (26a, 26b; ', 26b') for linear forced transmission along said axis of rotation at equal distances to or away from each other. Device according to Claim 1, characterized in that the guide rollers are arranged non-rotatably on a common shaft and that this is motor-driven, so that the guide rollers can further supplement the function of the feed roller. Device according to claim 1 or 2, characterized by a position (11, 16) of the position of the piece of wood at a certain position, which sensor is adapted to trigger a start signal to the actuator (15a, 15b) which moves the guide rollers towards the central plane of the machine tool. Device according to Claim 3, characterized in that the sensor is formed by a cylindrical roller which is non-rotatably and non-displaceably arranged on a common horizontal axis between the guide rollers and which preferably has the same diameter as the feed roller. Device in a circular saw according to one of the preceding claims, characterized in that the horizontal shaft is arranged on the lifting boom (19) of the sawing machine instead of a conventional feed roller. li 7 69263 Device according to one of Claims 1 to 5, characterized in that the rigid mechanical joint system comprises two horizontal, parallel toothed racks (24a, 24b) which are arranged with their vertical gaps and rows of teeth (13a, 13b) facing one another. parallel to each other and to said common horizontal axis, and a gear (14) arranged in said vertical space to engage both rows of teeth, and that each rack is provided with a transfer (26a, 26b) for moving its own roller along said axis. Device according to claim 6, characterized in that for said mandatory transmission a motor is provided which drives either the second rack in a straight line or a gear with a rotational movement. Device according to one of the preceding claims, characterized in that the two guide rollers can be moved to the side by the motor (35) at equal distances in the same direction. Device according to Claim 7 or 8, characterized in that the motor and / or the auxiliary motor is a double-acting hydraulic cylinder piston unit (15a, 15b, 35). Device according to one of Claims 1 to 5, characterized in that the mechanical articulation system comprises a screw spindle (34) with two counter-rising threads, two transfer arms (20a1, 2bb *) with nut threads for each screw thread and for each guide roller. gripper, and a drive motor (32) for the screw mandrel. 8 τ 69263