SAW MILL

Abstract: This invention relates to an apparatus in a saw mill enabling partly sawing logs to blocks, partly sawing blocks to boards and planks, the saw mill comprising an elongated, movable saw table, on which the log/the block is intended to rest, and a saw means, which is intended to carry out the sawing itself. According to the invention the apparatus comprises two hydraulically controllable holding means (4, 5) which are fastened on the saw table (1) at its one long side and are intended to hold the log when sawing the same to blocks, and a hydraulically controllable pressing means stationarily arranged outside the saw table for utilization when sawing blocks to boards and planks. Both the holding means (4, 5) and the pressing means (7) are possible to turn down to an active holding/pressing position and possible to turn up to an inactive resting position, the pressing means (7) being intended to take an inactive position, when the holding means (4, 5) take their active positions, and vice versa, whereby the holding means (4, 5) movable together with the saw table freely can pass the stationarily arranged pressing means (7).

Description: SAW MILL This invention relates to an apparatus in a saw mill enabling partly sawing logs to blocks, partly sawing blocks to boards and planks, the saw mill comprising an elongated, movable saw table, on which the log/the block is intended to rest, and a sawing means, intended to carry out the sawing itself. With previously known technique it has appeared to be difficult to carry out these two types of sawing operations by one and the same saw mill. A first problem with known technique is to achieve a secure and effective holding of the log/the block during the whole sawing procedure. A second problem is difficulties to achieve an effective adjustment of the log/the block prior to the sawing operation. This invention intends to remove the problems with known saw mills and provide an apparatus in saw mills which enables effective sawing of logs to blocks and of. blocks to boards and planks. This has been made possible by an apparatus of the kind mentioned by way of introduction which has the characterizing features appearing from the claims. Due to that fact an extremely secure holding of the log/the block is achieved during the entire sawing procedure. Furthermore, the novel invention enables an extremely accurate adjustment of the log/the block prior to the sawing procedure. The remaining features of the invention appear below from the description of a preferred embodiment of the invention and from the claims. The preferred embodiment- shall be described more closely with reference to the accompanying drawings, where Fiσ. 1 shows a plan view of a saw mill having the apparatus according to the invention, Fiσ. 2 shows a view of the appara- tus according to the invention, taken along the line 11-II of Fig. 1, a holding means being in an inactive position, whereas a pressing means being in an active position, and Fig. 3 shows the same view as in Fig. 2 but with that difference that the holding means is in an active position, whereas the pressing means is in an inactive position. Referring to Fig. 1 is shown there a saw mill comprising an elongated saw table 1 on which a log 2 is positioned and which is movable forwards and backwards in its longitudinal direction. The saw table 1 moves in the direction of the arrow P during sawing. The log 2 is intended to be sawn by a saw means which in this case comprises a circular saw blade 3. The saw means 3, which is driven in a suitable way, for instance b means of an electric motor, may of course instead be for in¬ stance a band saw blade. The saw mill comprises two holding means 4, 5 which are fastened to one of the longitudinal sides of the saw table and are intended to hold the log stationarily during the sawing procedure. The operation of the holding means is made in a hydraulic way by valve means 6 which are arranged on the saw table. The saw mill also comprises a hydraulically operable pressing means 7, i.e. the pressing means can be operated hydrauliccaly, for utilization when sawing blocks to boards and planks. A movable stop means 33 mounted on the saw table pre¬ vents the log from sliding backwards. Referring to Fig. 2 is shown there one 4 of the holding means more closely. The holding means comprises an upper 8 and a lower 9 clamping arm which are directed essentially perpendi- cularly to the longitudinal direction of the saw table 1 and which are intended to be able to be operated by means of a first hydraulic plunger cylinder 10. When pushing out the plunger 11 from the cylinder 10, which happens when the holding means shall take its active holding position (see Fig. 3), the upper clamping arm 8 is pivoted about a hinge 12 so that the arm 8 goes into engagement with the top side of the log. At the same time the lower clamping arm 9 about a hinge 14, which arm normally has an essentially horizontal position and which is an integral part of a lever, the other part of which comprising a bar 13 directed downwards, the lower part of the bar being connected to the lower part of the plunger cylinder, whereby the lower clamping arm 9 is forced upwards to contact with the underside of the log. Due to that fact the log is held statio¬ narily in an extremely secure way by pressure from the two clamping arms, which is of greatest importance in order that the sawing operation shall be made in a secure way and that the saw cut shall be perfect. The holding means 4 further comprises a second hydraulic plunger cylinder 15 by means of which the position in the cross-section of the saw table of the upper 8 and the lower 9 clamping arm can be adjusted 10-15 cm. Due to that fact the adjustment of the log prior to the sawing operation can be made extremely accurate which also contributes to an effective sawing operation. The adjustment direction of the log is suitably achieved by a laser means 16 (see Fig. 1) which is arranged in the rear portion of the saw mill. In Fig. 2 the pressing means 7 is shown more closely. This means 7 is intended to hold the block sawn from the log stationarily by pressure when sawing this one to boards and planks of a predetermined thickness. In that connection the pressing means coopertes with a measuring means 17 for an accurate adjustment of the measure of thickness. The pressing means 7 is arranged in a frame 18 outside the saw table 1 on the other side of the same in relation to the holding means 4. This fact and the fact that both the holding means and the pressing means can take an upper inactive position and a lower active position, the pressing means and the holding means at the same time taking opposite positions, has the consequence that the holding means movable together with the saw table when moved in the longitudinal direction of the log is not prevented by the pressing means. The pressing means 7 comprises an essentially horizontal girder 19 projecting in over the saw table 1 in a direction which is essentially perpendicular to the longitudinal direc¬ tion of the saw table. Right out on the girder 19 is a lever 20 articulately arranged. This lever comprises a short, upwards- directed portion 21, the outer end of which is articulately connected with the outer end of the plunger 22 of a third hydraulic cylinder 23. The portion 21 cooperates with a long portion 24, directed downwards, forming an angle of about 90° with the portion 21. Right out on the portion 24 there is a rotatable wheel means 25 which is intended to roll on the outside of the block/log. When the plunger rod 22 of the plunger cylinder 23 is extracted, the pressing means 7 takes a lower, active pressing position, whereas the means 7 takes an upper, inactive resting position when the plunger rod 22 is retracted, which appears from Fig. 3. The pressing means 7 automatically takes this upper position when the holding means 4 has taken its lower, active holding position. The rear portion of the hydraulic cylinder 23 cooperates with a cam means 26 on its one side, whereas the cam means 26 cooperates with a preadjustable spring 27 on its other side. Furthermore, there is a hydraulic valve 28 on which the cam means is arranged and which controls the oil flow to the fore portion and the rear portion of the plunger cylinder 23 via conduits 29, 30. In normal position the adjusting cam 26 of the hydraulic valve 28 is influenced by the rear portion of the cylinder 23 in that way that the hydraulic pressure keeps the wheel means 25 in a lifted position. When an adjusting means 31 on the front side of the saw table is lifted, the hydraulic valve 28 is removed a little distance from the cylinder attachment, the adjustment cam 26 switching over the oil flow from the one side of the cylinder 23 to the other side of the cylinder, whereby the wheel means 25 is lowered. When the wheel means hits the periphery of the log/the block, the spring 27 is compressed by the cylinder 23 until the spring hits the adjusting cam 26 again. Thus, the counter pressure of the spring will determine the compressing pressure of the wheel means against the log/the block and the pressure becomes always the same independently of the varying dimension of the log/the block. The desired compressing pressure can be changed by means of a pressure determiner 32 positioned in the rear gable of the spring house. The apparatus is so designed that when the holding means changes the position from an inactive one to an active one, the pressing means automatically changes its position from active to inactive. This is made possible by the means 31 (see Fig. 3) which influences the hydraulic valve 8 to raise the wheel means. The saw table is driven steplessly by a hydraulic motor which is adjusted by means of a hanging hydraulic valve which is provided with a pistol grip. When sawing logs the following happens. The log is put on the saw table 1 and is clamped firmly by means of the clamping arms 8, 9 which go into clam¬ ping position when the plunger 11 projects out of the first hydraulic cylinder 10. If the pressing means would not be in an inactive resting position, i.e. be uplifted as is shown in Fig. 2, the pressing means will automatically take this resting position when the clamping arms 8, 9 take the clamping posi¬ tion. Due to that fact the holding means go free from the pressing means during the movement of the saw table when sawing. Then the round log is sawn in such a way that an elongated block preferably with a square cross-section is shaped. When this block continuously shall be sawn to boards and planks, the holding means 4, 5 are turned up, whereas the pressing means 7 is turned down so that its wheel means 25 is put against the outer vertical side surface of the block and forces this one against the measuring means 17 which is adjus¬ ted in that way that when the saw table is moved in the direc- tion of the arrow P, boards and planks with predetermined thickness are sawn out. In that connection the wheel means 25 of the stationary pressing means 7 rolls on the vertical side surface of the block. The invention is of course not limited to the described embodiment but can be modified within the scope of the follo¬ wing claims. The pressing means for instance can be modified in that way that it is provided with a hydraulic motor giving the wheel device of the pressing means a peripheral velocity which is in accordance with the movement velocity of the saw table, i.e. the feeding velocity of the block. Due to that fact the stop means 33 could be eliminated.

Claims: Claims 1. An apparatus in a saw mill enabling partly sawing of logs to blocks, partly sawing of blocks to boards and planks, the saw mill comprising an elongated, movable saw table, on which the log/the block is intended to rest, and a saw means which is intended to carry out the sawing itself, c h a r ¬ a c t e r i z e d in that the apparatus comprises two hydrau¬ lically operable holding means (4, 5) which are fastened on the saw table (1) at its one long side and are intended to hold the log stationarily when sawing the same to blocks, that the apparatus further comprises a hydraulically operable pressing means, which is stationarily arranged outside the saw table, for utilization when sawing blocks to boards and planks, which means is intended to cooperate with a measuring means (17) in such a way that the block that shall be sawn is intended to be forced against the measuring means, whereby boards and planks with a predetermined thickness can be sawn in an accurate and secure way, and that both the holding means (4, 5) and the pressing means (7) are possible to turn down to an active holding/pressing position and possible to turn up to an inac¬ tive resting position, the pressing means (7) being intended to take an inactive position, when the holding means (4, 5) take their active positions, and vice versa, whereby the holding means (4, 5) movable together with a saw table can freely pass the stationarily arranged pressing means (7) . 2. An apparatus according to claim 1, c h a r a c t e ¬ r i z e d in that each of the holding means (4, 5) comprises an upper (8) and a lower (9) clamping arm, which can be hydrau¬ lically moved to or from each other, in holding position the log being intended to be clamped between the clamping arms. 3. An apparatus according to claim 2, the clamping arms (8, 9) in holding position having a direction which is essenti¬ ally perpendicular to the longitudinal direction of the saw table (1), c h a r a c t e r i z e d in that the clamping arms (8, 9) are movable in a hydraulic way essentially in the cross-section of the saw table (1) for a correct adjustment of the log. 4. An apparatus according to any one of the preceding claims, the pressing means (7) .being arranged in a frame (18) outside the saw table on the other side of the same in relatio to the holding means (4, 5), c h a r a c t e r i z e d in that the pressing means (7) comprises an essentially horizontal girder (19) projecting in over the saw table (1) in a direction which is essentially perpendicular to the longitudinal direc¬ tion of the saw table (1) and a rotatable wheel means (25) which is intended to roll on the outside of the block/the log, and which is arranged at the outer end of an arm (24) , the inner end of which is articulately fastened to the outer portion of the girder (19) .

Inventors: ROENNBERG OSWALD, ROENNBERG, OSWALD
Applicants: ROENNBERG OSWALD, ROENNBERG, OSWALD
Application year: 1992
Main classification: B27B15
IPC codes: B23D59, B27B29