METHOD AND EQUIPMENT FOR WORKING BEAMS

Abstract: The invention concerns a method and equipment for the machining of logs. According to the invention, the drilling of holes, making of indentations and other machining operations done on the logs are performed consecutively with each machine tool doing only the task allotted to it. The equipment includes machine tools (14) for machining the ends of the logs and rotating devices (15, 18) for rotating the logs for the purpose of machining their other ends with the same equipment (14).

Description: METHOD AND EQUIPMENT FOR WORKING BEAMS This invention concerns a method and equipment for the machining of building logs. One type of method and equipment according to the invention is presented in the accompanying claims. One of the main problems in the conventional machining of logs required in timber buildings is that the work stages need a great deal of manual labour. As labour-intensive industries are seldom competitive, the aim is to introduce automation to this industry, too. Another drawback of conventional timber working with logs is that, in small industrial plants, many work stages are done manually or by very simple tools, with the result that their quality is often not very high and measuring inaccuracies may lead to problems in erecting the building and ensuring its compactness and other necessary properties in the later use of the building. A further drawback in the conventional method of log construction is that, so far, there has been no equipment available that is capable of performing all the necessary machining in the same very compact space while efficiently utilising the same machines to carry out a number of tasks. The normal situation is that the factory has one machine to perform one work task, while other work tasks are performed by different machines. The total investments are very large and in many cases separate equipment or manual labour is required to transfer the logs between machines. The purpose of this invention is to avoid the above-mentioned technical drawbacks and to achieve a method and equipment by which the machining of timber can be done in a way which is rational and saves manual labour. In addition, the purpose is to achieve equipment whose purchase price is advantageous, even though it performs a great variety of tasks. The above-mentioned and other benefits and advantages of the invention are achieved as is presented as characteristic of the invention in the accompanying claims. The invention presented here is based on the idea that log house factories, which normally need large areas for production, transfers and storage and which normally contain expensive, single-purpose wood-working machines scattered around the production premises, can, in accordance with the invention, be integrated into one "package" or whole comprising all the various machining and transfer stages of production. According to the invention, there is no need to acquire expensive, separate machines for performing particular machining operations, but rather, for the performance of each work stage, only the necessary tools and power devices to run them, combined with the automation to control them and give continuation impulses for the shifting of each log laterally to transfer equipment located as near as possible to the following work station. When the machinery at this work station receives the impulse from the transfer device, "transfer-to-end completed", it starts. When the machining is completed, a continuation impulse is sent from the machine to initiate the next transfer stage. The transfer does not start if the next work station is still reserved. The invention will now be described with reference to the attached figures which depict by way of example one possible embodiment of the invention without in any way restricting it to this embodiment. Figure 1 is a plan view of one embodiment of a plant according to the invention; Figure 2 presents a side view of the layout of the plant in figure 1 ; Figure 3 is the same kind of diagram as Figure 2 but now viewed from the opposite side to that shown in Figure 2; Figure 4 presents the same plant viewed from an angle which is ninety degrees from the viewpoint of Figure 2; and Figure 5 presents the same plant again, but now viewed from the opposite side to that shown in Figure 4. The figures show numerous intrinsically ordinary parts of the plant which are not meant, in any way, to limit the invention. On the contrary, any particular type of conveyor or lateral transfer equipment, for example, may be replaced by another type, without in any way affecting the whole inventive idea. It should also be noted that the purpose is to depict only one functional solution and to give guidelines for the whole plant. Thus many variations are possible without departing from the protective sphere of the invention. It should be further noted that the figures do not depict, for the sake of clarity, motors, power transmission equipment or other ordinary parts, because the selection of such equipment is a task which must be carried out by the people involved, on a case by case basis. In a log house production plant according to the invention, all machining work such as drilling, sawing, the making of notches or grooves is done by machine tool units, each of which carries out separate machining jobs for particular purposes. All machine tool units work with an up-to-down motion. Each of the machine tools, longitudinal or lateral transfer lines or line systems described in the following paragraphs receives control instructions from the adjacent functions on each side. In practice, this means that each machine tool indicates when the work stage it is meant to perform is actually performed and then switches on the transfer line to move the log forward to the next stage. At the same time, the machine tool gives a signal to the previous transfer device that it may begin the transfer of a log to the vacant place immediately the transfer forward has started. The orders are given in a step-by-step process as described above throughout the whole production process. Control takes place centrally in the control room which is marked " in the figures with the reference number 21 and from where there is visual contact with the different stages of production. The automation system also allows for the manual use of each machine or piece of equipment on a step-by-step basis. The production steering system also includes an ADP program which has been developed for the plant's production and directs the work of each machine tool. Accordingly, when a log arrives in the plant, the program orders the machine tools to make the necessary machining operations and ensures that, as the log advances through the plant, the right machining tasks are done at the right place and time. The exact, ultimate position in the building of each log transferred to the beginning of the line is known from the outset. In practice, some machine tools carry out their machining task on the log, while others do not, which means that the up-to-down movements of the machine tools are either performed, or they are not performed. Also included in the steering system are ordinary sensors, detectors, limit switches and single or twin function switches which are located on the lines and machines to identify movements and positions. A very important stage, for the invention, is the drilling of the first "dowelling hole" through the timber in conjunction with the trimming of the log ends by the first machine tool. In the production presented here, this is the hole from which all measurements are taken and from which the timber is attached exactly in place, at various production stages, by means of a dowel included in the equipment. The logs are fastened by dowels during the whole upper and lower lateral transfer period on the lateral transfer line, while travelling between the working positions of machine tools 14.1 - 14.5, in which a specified machine tool unit may perform an operation on a specified log while the other logs pass by the machine without it starting. The functions of a plant according to the invention are described in what follows with reference to the figures and particularly to Figure 1. Although the functions of the method and equipment according to the invention become very apparent from Figure 1 , reference can at the same time be made to Figures 2-5 in which the equipment of Figure 1 is presented as viewed from different perspectives and in which the plant's various parts and locations with respect to each other are better outlined. A dressed log is lifted onto the initial line 1 which transports it to a stopper which stops the line so that the log's head is under the head trimming and drilling machine tool unit 2. The head is trimmed and holes are simultaneously drilled through the log at certain distances, in this case 30 cm and 90 cm, from the trimmed head of the log. When the above machining is completed and the machine tools are raised, the longitudinal transfer line 5 starts and transfers the log exactly a specified distance, which equals the log's planned length. The control system and software define the stopping point and receive the necessary information on the movement of the log, so that the next machining point is 30 cm from the above- drilled hole which therefore is used already at this stage as a measuring point. When the line has stopped, the sawing and drilling machine tool unit 3 starts and the log is cut to length. Now holes are drilled through the log's other newly- trimmed end, at 30 cm and 90 cm from the end. The longitudinal transfer line 5 starts and transfers the log to the end of the line, whence the drilling tool units 4, including the last drilling unit, start to drill as many adjacent holes in the direction of the log's advance as needed to ensure that the length of each log between the holes drilled at 30 cm from each end is covered with drilled holes at 60 cm intervals. When the drilling functions have been performed, the lateral transfer device 6 is started. This raises the log from the line and transfers it laterally to another lateral transfer device 7 which continues the transfer to the longitudinal transfer line 8. If the way is not yet clear for the following stage, the transfer devices 7, 8 can stop in a sending/receiving stage to wait for the freeing of the following stage. The plant's lead time is determined by the time that elapses from the starting of longitudinal transfer line 1 to the starting of lateral transfer device 6. Each production stage after this probably requires less time than the previous, although the plant naturally runs according to the same production rhythm. Lateral transfer device 7 transfers the log to the longitudinal transfer line 8 which starts and transfers the log in the longitudinal direction to line 12 according to the instructions concerning length of transfer, etc. that the automation system determines, stopping the movement at the point of the drilling machine tool unit 9 in the case that an attachment groove or corresponding must be made in the side of the log for the purposes of attaching to a wall surface or, for example, the attachment of a cabinet system. If the wall is to be attached to the left side of the log, the log stops at the joint machine tool 10, while if it is to be attached to the right sideof the log, the stopping place is correspondingly at the machine tool 11. After the above-mentioned stages performed by machine tools 10 and 11 , the longitudinal transfer line 12 shifts the log to the end of the line in question. The lateral transfer line 13 starts and transfers the log to the lateral transfer line system 15, whence the log is set into dowels located on line 15 via the holes drilled 30 cm from each of the log ends. Thus, the log is precisely fixed in the right position. The above describes the progress through production of the first log. It is clear that, for the flexible, continuous operation of the plant, it is important to keep it at full capacity the whole time. Thus, when a log is transferred to the longitudinal transfer line 5, a second log is lifted to the beginning of the longitudinal transfer line 1. On the other hand, the first log may have been so long that, in sawing to size, the machine tool unit 3 may have been left with a piece from the first log which can be utilised. Therefore, this piece is handled in the plant next and only after that will a new dressed log be lifted onto the beginning of the line. The log on the initial line 1 is moved forward immediately the lateral transfer device 6 has started to transfer a log from line 5. The log next shifting to longitudinal line 8 transfers forward when the first delivered log is transferred to the lateral transfer line 15. Thus, logs enter production one after the other in such a way that the number of logs being handled is always the number needed for one whole wall. Next, the lateral transfer line 15 moves one metre in the lateral direction, for example, this distance being exactly the same as the distance between machine tools 14.1 - 14.5. Each time the transfer line transfers a log forward, a new log enters the initial line 1. Although the logs stop at each of the machine tools 1 - 5, only that machine tool starts which is needed to perform the desired result according to the automatic control system. As mentioned above, the log is fixed precisely in the right position, due to the dowels penetrating the drilled holes, for which reason extremely accurate tolerances are achieved at each work stage. The machine tool units 14.1 - 14.5 each perform their own special task on one end of each log. Generally, this relates to the making of indentations etc. required in the case of corner joints that have male and female parts. In addition, the tools in section 14 can be used for the machining required in making extra thermal insulation near the ends of the logs. The logs are thus transferred laterally by line 15 under the machine tool units so that these tools can perform all necessary machining tasks. When the final operation of the machine tool units 14 has been performed, the log is transferred at the end of line 15 through a 180 degree turn to the part of the line that travels under line 15 towards the longitudinal transfer line 16. Upon reaching line 16, the log begins to progress forwards as instructed by the software. The logs are accompanied to line 16 by a lever mechanism. Line 16 now transports the logs to longitudinal transfer line 17 which transports each log to a position that corresponds to that particular log's location in the completed wall. At this stage, the positions of windows and doors are also taken into account. The lateral transfer line system / inspection station 18 lifts each log from line 17 and transfers it to the upper end of the line system / inspection station 18, starting from the uppermost log of a wall section, followed by the next log under it, and so on, so that the logs are piled in exactly the order and in the positions they will ultimately occupy in the building. The whole wall of the building is thus always collected in the order in which it can be erected. At this stage, all the necessary machining and drilling has been performed in the sides of the logs, and all the necessary machining at one end of each log. The machined log ends are now lying in the same direction in the inspection station. A visual inspection can be carried out before the logs are sent on their way for machining of the other ends. After the inspection, the transfer and rotating device 19 is started and transfers the wall logs via a lateral transfer line system a certain distance away from a longitudinal transfer line (e.g. 17), which makes it possible to rotate, through 180 degrees, the whole line system / inspection station 18. The lateral transfer device 19 first transfers the lateral transfer line 18 which has rotated in a semi-circle back to its starting point beside longitudinal line 17, after which the lateral transfer device 20 starts and transfers the nearest log to longitudinal transfer line 8 which transports the log to lateral transfer device 13 to be lifted and transferred to via longitudinal transfer line 12 to lateral transfer line 15. The next log from inspection station 18 starts to move at this stage. As is apparent from the foregoing, the logs are now, after having been rotated180 degrees, again approaching the earlier described machining stages of the log ends. All logs advance through the machining stages with their other end foremost in the same way as they did during the machining stage for the first ends. When the other ends of the logs have been machined, the logs are transported in the above-mentioned way to inspection station 18 in an order completely correponding to the wall of the coming building, but now that side of the log is uppermost which was uppermost at the time the log was originally fed into line 1. After this, the logs are inspected and are automatically removed from the inspection station in a way corresponding to that previously described.- Now the logs no longer return to line 15, but are fed out of the plant by longitudinal line 12, ready-machined for further processing stages, such as painting. During the machining stage of the other ends of the logs, no new logs are fed into the initial line of the plant, but the person performing the feeding now works in supervision and inspection duties at the inspection station. Thus savings in labour costs are achieved. When all the foregoing stages are completed, the making of a second wall can start, with the logs being fed one by one into the plant in a way completely corresponding to that described in the foregoing. From the point of view of the invention, it is irrelevant what kind of log building is being created. It is clear that it is a routine task for professionals in this field to plan and instai machine tools and equipment in order to achieve appropriate machining at the required place, using the general principles described in the foregoing. Thus, it is also clear that, in making log structures in which the logs are assembled in even layers, the profiles to be machined are different from what they are in structures in which logs equipped for the conventional type of corner joints are made. In a plant according to the invention, it is also possible to make the indentations required for additional thermal insulation, etc. in the ready logs, and also to machine logs which make a different layer on the room side of the wall structure. These machining stages are done by the machine tools 14, which are meant not only for the machining of log ends, but also for other kinds of machining. These machining stages are performed at the machine tool designed for that purpose as the logs travel from machine to machine in line 15. In acting according to the invention, it is possible to use, instead of a log extended by means of so-called finger splice, an extension of the log by using a type of splice in which suitable counter joint surfaces are machined at the ends of the log to be extended and the log that will extend it. The joints are completed on site when erecting the house. Thus, a remarkable advantage can be achieved in that it is possible to use the raw material exactly and avoiding the handling of very long logs at the plant and on the work site. A large number of different kinds of devices for the removal of sawdust, dust and other materials arising from the production are naturally also a part of equipment according to the invention.

Claims: Claims 1. A method of machining logs, in which the logs are stopped at machine tools designed to drill holes, make indentations and do other tasks for the purpose of performing the particular machining tasks programmed for each log, characterised in that, in order to machine the log ends, the logs are transported in a step-by-step manner from machine tool to machine tool, each performing a certain task in the machining of one end of each log, and that the logs are rotated around their longitudinal axis and also around their transverse axis, and are returned to the afore-mentioned step-by-step machining stage for the purpose of machining the other end and other side of each log by the same machine tools. 2. A method according to claim 1 characterised in that, after the machining of one end of each log, the logs are stacked and arranged on an inspection station so as to form a whole wall, in positions that correspond to the real assembly situation, for the purpose of an intermediate inspection, and that the logs are then returned to the same machine tools as in the first work stage for the purpose of machining the other end of each log. 3. A method according to claim 1 , characterised in that, during the machining of their ends, the logs are transported while mounted on the production line and fixed in position by dowels fitted into holes drilled through the logs at an earlier stage. 4. A method according to claim 1 , characterised in that the logs are transported to both the first and second stage of machining the log ends on the same longitudinal conveyor and lateral transfer device. 5. A method according to any of the foregoing claims, characterised in that the logs are transported in the plant in opposite directions and in a way which exploits the conveyors' ability to move in different directions, for the purpose of allowing the equipment to operate in a facility with the smallest possible surface area. 6. Equipment for the machining of logs, including conveyors and machine tools, for the purpose of transporting logs from one machine tool to another, so as to perform machining tasks such as drilling, making indentations and other similar jobs programmed for each log, characterised in that the equipment includes, in consecutive order, machines (14.1 - 14.5) for machining one end of each log, a rotating device (18) for rotating the logs 180 degrees around their transverse axes, and conveyors and transfer devices (8, 12, 13, 15, 16, 17, 20) for returning the logs to the machine tools (14) for the purpose of machining the other end of each log. 7. Equipment according to claim 6, characterised in that it includes dowel-like devices to keep the logs precisely in the planned positions, with the aid of holes drilled through the logs, during the whole time that the machine tools (14) are working. 8. Equipment according to claim 6, characterised in that the rotating device (15) is a transverse conveyor containing a continuous transportation loop and that the logs are rotated by the return loop part. 9. Equipment according to claim 6, characterised in that the rotating device (18) is a table rotating essentially on the horizontal plane. 10. Equipment according to claim 6, characterised in that all the machine tool units for the logs are located in a tightly packed, consecutive and parallel arrangement.

Inventors: MYYRYLAEINEN ESA AULIS, MYYRYLAEINEN, ESA, AULIS
Applicants: FINFRE OY, MYYRYLAEINEN ESA AULIS, MYYRYLAEINEN, ESA, AULIS
Application year: 1998
Main classification: B27M3
IPC codes: B27M1