FI56326C - MASKIN FOER SKAERNING AV FANER ELLER LIKNANDE SKIVFORMIGT MATERIAL - Google Patents

Description

E5F1 [B] (11) NOTICE OF ADVERTISEMENT

ΉΒΓα lj UTLÄGGN I NGSSKRIFT J O

C (45) Patent granted on 10 01 1930 J Patent aeddelat '(51) Kv.lk.' / Int.CI. * B 27 I 5/08 FINLAND — FINLAND (21) Ptt «nttlhtk * mui - Patmtameknlni 126 k / ^ k (22) Haktmlspllvi - Antöknlnpdaf 2 ^ .0 ^ .7 ^ (23) AJkupUvl — Giltl | h «tida | 2 ^ .0 ^ .7 ^ (41) Tullut julklMkil - Bllvlt offantllg 25.10.75

Patent and Registry Administrators ..... ,. ,, ...

_. (44) Date of dash and shield. -

Patents and Regulatory Affairs Antekan Utlafd oeh utUkriftan publlesrad 28.09-79 (32) (33) (31) Requested stuolkwi — Begird priority (71) Durand Machine Company Ltd., 101-llth Street, New Westminster,

British Columbia V3M 1 + C * +, Canada (CA) "(72) John E. Hards, Delta, British Columbia, Canada (CA) (7 * 0 Berggren Oy Ab (5 * +) Machine for cutting plywood or similar sheet materials - The mask is made of a fan or a shiny material

The invention relates to a machine for cutting plywood veneer or similar sheet-shaped materials continuously, of varying widths.

Because the cutter is primarily designed for cutting plywood veneers, it will be described in connection with these.

The veneer is peeled from the supports with veneer lathes, after which it enters a cutter which cuts off the defects and cuts the veneer to the desired width, which is done by controlling the movements of the veneer. So far, "one veneer cutter has not been able to work fast enough to produce the output of a conventional veneer lathe, so the latter has had to be operated at a slow speed, or several cutters have been needed to handle the output of one lathe.

Most of the cutters used by current plywood mills are of the guillotine type, as described in U.S. Patent No. 2,394,324. In these, the knife acts like a guillotine against a fixed anvil. As a result, the knife stops the veneer for a short time during each cut. The feed speed of these cutters is limited to approximately 91.5 meters per minute when cutting wide boards, and in several factories they are operated at much lower speeds, so that small or variable widths are cut at approximately 45.7 to 61 meters per minute. At these low speeds, part of the veneer moves while the cutting blade stops the other part, and this can cause jams or constrictions that either cause stops or make it more difficult to handle the veneer pieces.

In the commonly used guillotine-type cutter, the impact force of the knife is obtained from a very strong air cylinder with a normal diameter of 20 cm and an impact length of 20 cm. These cylinders require expensive and large valve systems to accelerate fast enough. The cylinder must be large due to the mass of the movable knife and transmission devices. High speed and high resistance cause serious cushioning and maintenance problems when the knife stops. A large cylinder requires a very precise air supply; otherwise, inaccuracies at the intersection will result. To reduce resistance, the transmission devices used between the air cylinder and the knife must be small, and as a result, they wear out quickly. In addition, as the knife moves upward after cutting, the veneer pressing against the knife tends to rise with the knife, and the veneer may break or jam if the feed holders do not work exactly right. These holders must provide some sliding space, resulting in inaccurate cutting, and this type of cutter is very noisy.

The operating staff of the factories has long wanted a cutter whose knife moves with the veneer when cutting. This type is commonly known as a drum cutter, as described in U.S. Patent 3,029,675. A drum cutter has one knife or two diametrically opposed knives, but these cut only predetermined veneer widths, and due to the high inertia of the drum, the clutch brake cannot withstand the brake. fast enough to perform variable surgeries.

The rotary cutter according to the invention greatly reduces and practically eliminates all the above-mentioned disadvantages. It has the advantages of a drum cutter, but not its disadvantages. The features of the invention appear from the following claims.

The disadvantages have been overcome by using in this cutter a thin cutting blade whose mass has been reduced so that it can be stopped and started with very little resistance. The length of the movable veneers is the final length of the plywood sheet to be made, transverse to the direction of movement of the veneer. In other words, the veneers to be cut are more than 2.4 meters long, and the cutting blade must be of a corresponding length. To prevent the thin blade from bending or vibrating, it is held at a relatively longitudinal tension. The veneer support drum is positioned so that the cutting edge of the blade at least contacts the outermost surface of the drum when cutting through the veneer. The support drum of the machine is positioned so that the edge against the cutting edge of the blade adheres to its outer surface at the same time as the veneer is cut. This ensures that the blade penetrates perfectly along the entire length of the veneer. The support drum, the support drum and the rotation speeds of the blade are synchronized with the feed of the veneer so that the cutting edge of the blade moves in the same direction and with the same cue as when the veneer is cut through it.

Because both drums rotate all the time, they are not affected by inertia forces. The tension keeps the blade suitably rigid at all times, and the support drum supports the blade at the time of cutting. In a preferred embodiment of the invention, the edge opposite the above-mentioned cutting edge of the blade is also the cutting edge. In addition, the normal or rest position of the blade is that in which the blade is in a horizontal position, and cutting takes place with the blade in a vertical position. Thus, the blade only needs to turn half a turn for each cut. This, together with the lightness of the blade, makes it possible to cut very narrow strips from a moving veneer. In other words, a very small defect in a tree can be removed without losing very much wood. Prior art guillotine and drum type cutters are not able to operate fast enough to cut such narrow strips of plywood, so a lot of wood is wasted.

This mower has been used at high speeds and can reach speeds of 183 meters per minute. This makes it possible to increase the fortune production of many plywood mills with existing lathes. With the cutter according to the invention, other factories can remove expensive belt systems between the lathe and several cutters.

The fact that the knife can be precisely synchronized with the movement of the veneer, practically eliminates jams, automatic and manual handling of the veneer can be made easier and the holders can be simplified. It makes it possible to measure the veneer accurately in the cutter in continuous use by holding the veneer firmly with clamps that do not need to allow room for maneuver. Small electronic 4 5632 (.

ti, hydraulically or compressed air clutch brake units that are much more uniform than the air cylinders of cutters commonly used in the art to date, so that the cutting results are much more accurate. In addition, noise from the striking air cylinder and loose transmission devices has been eliminated. Furthermore, instead of clutch brake units, other various control units can be used, such as, for example, a half-speed clutch, a stepper motor, and the like.

A preferred embodiment of the invention is illustrated in the accompanying drawings, in which Figure 1 shows a top view of a rotary veneer cutter, Figure 2 is a longitudinal vertical section along line 2-2 of Figure 1, Figure 3 is a vertical cross-section along line 3-3 of Figure 2, Figure 4 is an enlarged longitudinal section 1 line 4-4, and Fig. 5 is a vertical cross-section along line 5-5 of Fig. 4.

In the drawings 10 there is a rotary veneer cutter comprising a pair of spaced apart end frames 11 and 12, between which is a support drum 15, a support drum 16 and a thin cutting blade 18.

The shafts 20 and 21 of the drums 15 and 16 are mounted on the frames 11 and 12 and extend through the wall of the body 11. The blade 18 is very thin, narrow and relatively long in the transverse direction of the machine. Of the blade shafts 25 and 26, the shaft 25 extends through the wall of the body 11, and the shaft 26 is mounted on the body 12. The blade 18 has a cutting edge 29 on one side thereof and although not absolutely necessary, it is preferable to provide the blade with a second cutting edge on the opposite side of the blade. 30.

Since it is desirable to keep the blade 18 under tension during use, the outer end of the shaft 25 is secured by a suitable support 34 to a rod 36 having opposite ends connected to the piston rods 39 and 40 of the liquid cylinders 41 and 42 supported by the wall 11 of the body. is introduced into and out of the cylinder 41 by pipes 44, and likewise liquid or air is introduced into and out of the cylinder 42 by means of pipes 45. Since the control devices of the liquid or air systems used with the cylinders 41 and 42 are known, they have not been described or described. here. In any case, the pressure is usually maintained by the tubes 44 and 45 so as to pull the rod 36 horizontally straight out of the machine and thus keep the blade 18 in tension.

Any other suitable device can be used for this purpose.

Suitable devices are provided for rotating the drums 15 and 16 and the blade 18.

One such suitable device is illustrated in Figures 3, 4 and 5. An electric motor 50 mounted on a base 51 projecting from the support 11 is connected to a drive shaft 53 to which a gear 54 is fixedly attached. This gear is connected by a chain 55 to a second gear 56, fixedly attached to the shaft 21 of the support drum 16. The second gear 58 is fixedly attached to the shaft 21 and connected by a chain 59 to a gear 60 fixedly attached to the shaft 20 of the support drum 15.

The second gear 64 is fixedly attached to the motor shaft 53 and connected by a chain 65 to the gear 66 of an electrically, hydraulically or compressed air clutch brake 67. The clutch brake is connected to a gear 70 which communicates with the second gear 71 by a shaft 72. A gear 73 mounted to this shaft is connected to a shaft 73 to a gear 76 mounted on the shaft 25.

Thus, the motor 50 drives the drums 15 and 16 continuously while the machine is running and rotates the blade 18 according to the control of the clutch brake 67. The clutch brake is actuated by signals from a sensor 80 mounted above the machine feed conveyor 82. The sensor is positioned in front of the device 10 with respect to the direction of travel of the veneer indicated by arrow 84 in Figures 1 and 2.

When the sensing device detects an error in the veneer being transported towards the device 10, it sends a signal, and after a suitable delay, the clutch brake 67 engages to rotate the blade 18 so that it cuts longitudinally from the right point of the veneer. The sensor and delay mechanisms are the same as those used in this field in a guillotine-type cutter, so they are well known and thus do not require a description here. The sensing and timing device also includes a device that uses a blade to cut the veneer to the desired width with respect to the direction of movement of the veneer. If the veneer is slightly more than 2.5 meters as measured in the transverse direction of the conveyor 82, the blade is usually used to cut it to a width of slightly more than 1.25 meters in the direction of movement of the veneer.

6 5632b This control unit is also a standard tool.

The sizes of the different gears and drive gears between the motor 50 of the drive system and the drums 15 and 16 and between said motor and the clutch brake 67 and the blade 18 are such that the speed of movement of the cutting edges 29 and 30 in their circular path is the same as the outer surfaces of the drums 15 and 16. These speeds are also synchronized with the movement of the veneer so that the veneer moves at the same speed as the surface of the drum as the veneer passes over the surface of the drum 15.

A standard type of veneer holding device is shown at 90 in Figures 1 and 2. The feed conveyor 82 is formed of a plurality of endless belts 92 arranged side by side, and above each belt 92 and in contact with each belt 92 there is a holding belt 94. Each holding belt 94 rotates around pulleys 96 and 97. operated synchronously at the speed of the conveyor belt 92. The driving force for driving the conveyor 82 and the holding device 90 can be taken from the motor 50, or the conveyor and holding device can be driven by a separate motor 98, Fig. 1, so that this is synchronized with the motor 50. In this example, the motor 98 drives the conveyor 82 by means of a chain 102 and the retaining belts 94 by means of a chain 104 so that the drive wheels 105 reverse the direction of movement of the chain 106.

Since the veneer is not stopped during the cutting operation in this machine, the holding device can firmly grip each piece of veneer so that slipping does not occur as a certain portion of the veneer passes from the sensor to the cutting blade 18. Thus, the veneers always move the same distance between the sensor 80 veneer.

When the sensor 80 detects an error in the veneer passing under it, a cutting signal is generated, and when the same error arrives at the drum 15, the switch 67 causes the blade 18 to rotate half a turn. This causes the cutting edge 29 (when the parts of the device are in the position shown in Figure 2) to pivot down and cut through the veneer along the desired line as the veneer moves over the drum 15. Since the blade, veneer and drum all move at the same speed, the veneer does not have to stop when this happens. If the second signal is transmitted immediately after the first, the cutting edge 30 turns and cuts through the veneer. Therefore, with this device it is possible to cut very narrow strips of veneer, so that the minimum width of these strips is determined during that time.

Claims (8)

A machine for continuously cutting plywood veneer or similar sheet-shaped materials, of varying widths, characterized by a rotating support drum (15) over which the veneer to be cut moves, a thin steel (18) having at least one cutting edge (29) and rotatably mounted on the support drum (15). ) and adapted to rotate about a longitudinal axis parallel to this drum, with the tefa positioned relative to the drum such that the cutting edge (29) of the blade cuts the veneer with the drum (15) as the cutting edge passes the rotating support drum (16) above the blade , parallel to the blade and positioned so that the edge (30) opposite the cutting edge (29) of the blade rests thereon when cutting the cutting edge through the veneer with the support drum (15), and means (50, 65, 67, 75) for rotating the blade after cutting the command signal veneer from the desired point. β 56326 Device according to claim 1, characterized by a device (67) for stopping and braking the blade (18) after its cutting edge (29) has cut the veneer. Device according to Claim 1 or 2, characterized in that the edge (30) opposite the cutting edge (29) of the blade (18) is also a cutting edge. Device according to my claim, characterized by a device (67) for stopping and braking the blade (18) whenever one of its cutting edges (29, 30) has cut a veneer. Device according to Claims 1 to 4, characterized by a device (36, 41, 42) connected to the end of the blade (18) for keeping it under longitudinal tension. Device according to one of the preceding claims, characterized in that the means for rotating the blade (18) comprise a clutch brake (67) operatively connected to the blade, a power source (50) operatively connected to the clutch brake and a device (80) for optionally, the clutch brake is controlled to rotate the blade. Device according to one of the preceding claims, characterized by means (55, 56, 59, 60, 65, 70, 71, 75, 76) for synchronizing the rotation of the support drum (15), the support drum (16) and the blade (18) so that the cutting edge of the blade (29 or 30) moves at the same speed as the veneer passing over the support drum (15). 7 56320, which is required to turn the blade 18 half a turn. This time is very short because the blade 18 is very thin, so that the inertial forces have little or no effect on the blade. This very thin blade can be used to cut through veneer, as it is kept under tension always during use. In addition, the cutting edge 30 or 29, respectively, rests on the support drum 16 when the opposite cutting edge 29 or 30 cuts through the veneer with the support drum 15. Therefore, the blade can be made much thinner and lighter than otherwise. The surface of the drums 15 and 16 is made of a material to be replaced, such as a suitable plastic. For example, the surface of the drum 15 may be relatively soft so that the cutting edges of the blade sink somewhat into this surface as it passes, thereby ensuring that the blade cuts completely through the veneer. The surface of the drum 16 "may be slightly harder than the drum 15 so that it firmly supports the blade whenever one of its edges cuts through the veneer. Because the drums 15 and 16 rotate continuously, the cutting action does not cause inertia forces to be overcome for these drums. makes it possible to use a clutch brake that is much more precise and quieter than large air cylinders in prior art cutters, which also increases cutting accuracy.Each cut is made with the cutting edge of the blade, the veneer and the outer surfaces of the support drums moving in the same direction at the same speed. the holding device can grip the veneer very tightly, which increases the accuracy of the machine. Device according to one of the preceding claims, characterized by a drive device (98, 82) which moves the veneer over the support drum (15) at the same speed as the cutting edge (29 or 30) of the blade (18) moves.