A portable sawmill

Abstract

The invention relates to a portable sawmill (1) for sawing logs (100) into sawn timber comprising a beam (10) having a first end (11) and a second end (12), a first end member (20) and a second end member (30) provided to the beam (10), and a carriage (40) for connecting a chain saw (200) to the portable sawmill (1). The first end member (20) and the second end member (30) are arranged to receive a log (100) between the first and second end members (20, 30) and to secure the log (100) from its ends to the portable sawmill (10) in a direction parallel to the beam (10), the first end member (20) and the second end member (30) are arranged to support the beam (10) to the log (100) in a longitudinal and radial directions of the log (100).

Description

[0001] A PORTABLE SAWMILL

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a portable sawmill that can be used to saw logs into sawn timber at the location where the tree has been felled. The present invention relates to a portable sawmill and more particularly to a portable sawmill according to the preamble of the independent claim 1.

[0004] BACKGROUND OF THE INVENTION

[0005] Portable sawmills are known in the prior art for example with a commercial name Alaskan mill. With an Alaskan mill a frame is connected to a log transversely to a longitudinal direction of the log and then a chain saw is connected to the frame. The frame with the chain saw is pushed along the length of the log in order to get a sawn timber.

[0006] One of the problems associated with the prior art is that it is difficult to cut straight boards efficiently since the operator has to both push and operate the chain saw at the same time.

[0007] BRIEF DESCRIPTION OF THE INVENTION

[0008] An object of the present invention is to provide a simple and stable portable sawing mill which is easy to use.

[0009] The objects of the invention are achieved by a portable sawing mill which is characterized by what is stated in the independent claims The preferred embodiments of the invention are disclosed in the dependent claims.

[0010] The invention is based on the idea of providing a portable sawmill for sawing logs into sawn timber, the portable sawmill comprising a beam having a first end and a second end, a first end member provided to the beam, a second end member provided to the beam, and a carriage for connecting a chain saw to the portable sawmill. The first end member and the second end member are arranged to receive a log between the first and second end members and to secure the log from its ends to the portable sawmill in a direction parallel to the beam. The first end member and the second end member are arranged to support the beam to the log in a longitudinal and radial directions of the log. The carriage is movably connected to the beam and arranged to move along the beam between the first end member and the second end member.

[0011] In other words, the portable sawmill comprises a beam having a first end and a second end; but the beam may be formed from a single, one-piece beam or from plurality of beam sections forming the beam having the first end and the second end. The plurality of beam sections forming the beam may be connected to each other in many ways, but one way is to connect them with a connector provided inside the beam sections so that the connector extends from one beam section to another at the connection point (i.e. the joint of the beam sections) and is attached to the beam sections with screws. In a preferred embodiment of the invention the beam is formed from at least two beam sections which are connected together to form the beam.

[0012] The portable sawmill further comprises a carriage for the chain saw which the carriage is movable along a beam extending parallel to the log, i.e. the carriage is movable in a longitudinal direction of the beam. The chain saw is arranged to the carriage so that the blade extends transverse to the longitudinal direction of the beam. The chain saw is connected to the carriage so that the blade is on the side of the beam where the first end member and the second end member are arranged to receive the log.

[0013] The beam comprises the first end member and the second end member between which the log is placed, and the carriage is thus between the first end member and the second end member. The first end member and the second end member are arranged to extend in the direction away from the beam so that there is a gap between the beam and a log when the log is arranged between the first end member and the second end member. Alternatively, the first end member and the second end member are arranged to extend in the direction away from the beam such that no gap remains between the beam and the log when the log is arranged between the first end member and the second end member, but the beam is arranged to rest on the log.

[0014] The first end member and the second end member are arranged to support the beam to the log in a longitudinal and radial directions of the log. In other words, the portable sawmill is supported on the log so that the beam is arranged at a distance from the log and supported to the log through the first end member and the second end member both in the longitudinal direction of the log and in the radial direction of the log. This means that as the log is placed between the first end member and the second end member of the portable sawmill, the first and second end members connect to the ends of the log, therefore there is the support in the longitudinal direction of the log as well as in the radial direction of the log since the beam is a distance away from the log. Alternatively, when the beam is arranged to rest on the log, the first end member and the second end member are arranged to support the beam to the log in a longitudinal and radial directions of the log in addition the beam resting on the log. The commonality to both embodiments is that there is no direct support from the ground to the sawmill, but all support for the sawmill comes through the log itself. In other words, in both embodiments, the sawmill is fully supported by the log itself, eliminating the need for any direct ground support. In other words, the sawmill is entirely log- supported, which avoids any dependency on a direct ground support.

[0015] According to the invention the first end member is arranged to be movable along the beam, the first end member comprises fastening means which, in a locked state, fasten the first end member immovably to the beam.

[0016] In other words, the first end member is movable along the beam so that its place on the beam can be changed. This is especially advantageous when timbers of different lengths are sawn. The fastening means which fasten the first end member at its place on the beam are for example screws connecting the first end member to the beam or a bushing or pin arrangement in connection with the first end member. In the locked state the fastening means provide a locking effect to the beam structure or are arranged to go through the beam so as to lock the first end member to the beam or the locking is provided outside the beam so that there is a compressive effect, for example, with a screw-nut connection.

[0017] According to the invention the first end member comprises a first attachment head arranged to connect to a first end of the log.

[0018] In other words, the first end member forms a connection to the first end of the log by the first attachment head to connect the portable sawmill to the log. The attachment head may comprise for example a sharpened end that protrudes into the first end of the log, or a fork-like structure that provides a wider contact with the first end of the log.

[0019] According to the invention the first attachment head is movable in the radial direction of the log to adjust its position at the first end of the log.

[0020] In other words, the first attachment head is movable towards or away from the beam which the beam is arranged to extend parallel to the log provided between the first and second end member. The first attachment head is movable such that the first end member moves in relation to the connection with the beam.

[0021] Alternatively, the first attachment head is movable in the longitudinal direction of the beam but immobile in the radial direction of the log.

[0022] According to the invention the first end member comprises a first distance meter arranged to be placed on the log so as to contact the outermost surface of the log facing the beam.

[0023] In other words, the first distance meter of the first end member is placed on the outer surface of the log and in particularly on the outer surface of the log facing the beam. The first distance meter defines the thickness of the timber to be sawn from the log, i.e. the thickness of the board, so that the blade of the chain saw is placed between the first attachment head and the first distance meter which means that the first distance meter defines the distance of the blade from the beam. The thickness of the board needs to be the same throughout the board, so another distance meter is preferably needed on the other end of the log. The first distance meter keeps the blade of the chain saw on the same distance from the outer surface of the log at all times during sawing since both the first distance meter and the blade of the chain saw are connected to the same beam but on different members of the beam, the first distance meter on the first end member and the chain saw on the carriage.

[0024] According to the invention the first end member is connected to the beam with a connecting element such that the beam extends through the connecting element, the connecting element is movable along the beam to position the first end member relative to the beam in a longitudinal direction of the beam.

[0025] In other words, the beam is arranged to go through the first end member having a connecting element to connect the beam and the first end member together. The connecting element may be for example a plate arrangement such that there is one plate on the upper side of the beam and another plate on the lower side of the beam which the plates are connected together so that the beam extends between the plates. The plates can be connected for example with a bolt and nut connection which at the same time may function as fastening means for providing the locking effect to the beam structure to keep the first end member at place on the beam.

[0026] According to the invention the first attachment head is movably connected to the connecting element such that the first attachment head is movable in a direction transverse to the longitudinal direction of the beam.

[0027] In other words, the first attachment head is movable in relation to the connecting element of the first end member which connects the first end member to the beam so that the first attachment head is arranged to be movable relative to the beam, i.e. towards and away from the beam. This allows different sized logs having different sized diameters to be connected to the portable sawmill.

[0028] According to the invention the second end member comprises fastening means which, in a locked state, fasten the second end member immovably to the beam, and the second end member is connected to the second end of the beam immovably. Alternatively, the second end member comprises fastening means which, in a locked state, fasten the second end member immovably to the beam, and the second end member is arranged to be movable along the beam, when the fastening means are in an open state, to position the second end member relative to the beam.

[0029] In other words, the second end member may be movably arranged on the beam so that its position on the beam can be changed, or alternatively the second end member may be immovably arranged on the beam so that it is fastened to the end of the beam.

[0030] According to the invention the second end member comprises a second attachment head arranged to connect to a second end of the log.

[0031] In other words, the second end member forms a connection to the second end of the log by the second attachment head to connect the portable sawmill to the log. The attachment head may comprise for example a sharpened end that protrudes into the second end of the log, or a fork-like structure that provides a wider contact with the second end of the log.

[0032] According to the invention the second attachment head is movable in the radial direction of the log to adjust its position at the second end of the log.

[0033] In other words, the second attachment head is movable towards or away from the beam which the beam is arranged to extend parallel to the log provided between the first and second end member. The second attachment head is movable such that the second end member moves in relation to the connection with the beam.

[0034] Alternatively, the second attachment head is movable in the longitudinal direction of the beam but immobile in the radial direction of the log.

[0035] According to the invention the second end member comprises a second distance meter arranged to be placed on the log so as to contact the outermost surface of the log facing the beam.

[0036] In other words, the second distance meter of the second end member is placed on the outer surface of the log and in particularly on the outer surface of the log facing the beam which is the same way as the first distance meter on the first end of the log. If the first end of the log is where the sawing starts, the second end of the log is then where the sawing ends. The second distance meter defines together with the first distance meter the thickness of the timber to be sawn from the log, i.e. the thickness of the board. The blade of the chain saw, which is placed between the first attachment head and the first distance meter at the beginning of the sawing, emerges from the log between the second attachment head and the second distance meter at the second end of the log after the board has been sawn from the log. The thickness of the board needs to be the same throughout the board, which means that the first distance meter and the second distance meter are arranged to be at the same level relative to the beam.

[0037] According to the invention the first end member and the second end members are arranged to be connected to a log such that the first attachment head and the second attachment head are placed at the ends of the log, i.e. the first attachment head at the first end of the log and the second attachment head at the second end of the log, such that the beam rests on the log above the first and second attachment head, and the blade of the chain saw saws the board under the first and second attachment heads. This means that when the board has been sawn, the sawmill remains connected to the board that has been removed from the log by sawing.

[0038] In other words, the beam is directly on the log and the first and second attachment heads are right under the beam. The guide bar of the chain saw, i.e. the blade, is cutting the log under the first and second attachment heads. This means that the sawmill is attached to the top layer of the log that will be cut off during the milling and with each cut you the sawmill needs to be removed. According to the invention the portable sawmill is arranged to be supported solely to the log.

[0039] In other words, the portable sawmill is only supported on the log. This means that the portable sawmill is supported to a surface only through the log to be sawn. In still other words, the portable sawmill has no other connection to a support surface such as ground surface than through the log to be sawn with the sawmill.

[0040] According to the invention the carriage comprises attachment clamps for connecting the chain saw to the portable sawmill.

[0041] In other words, the chain saw is connected to the portable sawmill by connecting the chain saw guide bar to the attachment clamps of the carriage. The guide bar is connected via the attachment clamps to the portable sawmill so that a front part of the guide bar is connected to an attachment clamp arranged on one side of the beam in the carriage, and which the attachment clamp extends in the direction between the beam and attachment head of the portable sawmill so that the chain saw will be connected to a place which is under the carriage and above the attachment head of the portable sawmill. A back part of the guide bar is connected similarly to an attachment clamp arranged on an opposite side of the beam in the carriage so that the guide bar extends transversely to the longitudinal direction of the beam and the saw chain is towards the first end of the log. Alternatively, the chain saw will be connected to a place or location which is under the carriage and under the attachment heads of the portable sawmill. This means that the first and second attachment heads of the sawmill are above the guide bar of the chain saw.

[0042] According to the invention the attachment clamps are arranged to extend away from the beam so that the chain saw connected to the attachment clamps is between the first end member and the second end member. Further the attachment clamps are arranged to extend away from the beam so that the chain saw connected to the attachment clamps is between the first end member and the second end member and on the side of the beam where the attachment heads are located.

[0043] In other words, the chain saw connected to the attachment clamps is arranged between the first end member connecting to the first end of the log and the second end member connecting to the second end of the log so that the log can be sawn. However, the carriage comprising the attachment clamps is arranged on the beam so that the chain saw which is connected to the attachment clamps is between the first distance meter and the first attachment head connected to the first end of the log. The attachment clamps are arranged to extend outside the area of the log, which means that the carriage extends transversely to the longitudinal direction of the beam from which they extend away from the carriage to attach the guide bar of the chain saw between the first distance meter and the first attachment head.

[0044] According to the invention the attachment clamps comprise at least a first attachment clamp and a second attachment clamp which extend away from the beam on the opposite sides of the beam.

[0045] In other words, there are at least two attachment clamps so that the guide bar of the chain saw can be connected to the carriage to extend transversely relative to the longitudinal direction of the beam.

[0046] According to the invention the attachment clamps are adjustable so that a distance of the chain saw relative to the beam is adjustable.

[0047] In other words, the attachment clamps of the carriage are adjustable so that the position of the guide bar of the chain saw relative to the beam is adjustable. On the other hand, the adjustable attachment clamps can be used to adjust the position of the guide bar relative to the distance meter of the first end member so that the thickness of the board to be sawn from the log can be determined.

[0048] The attachment clamps preferably comprise a handle or an actuator with which the clamps can be operated. The attachment clamps provide a quick connection between the portable sawmill and the chain saw and allow any kind of chain saw to be connected to the sawmill. The attachment clamps are preferably arranged at a distance of 30 - 60 cm from each other, and more preferably at a distance of 40 - 50 cm from each other, and most preferably at a distance of 42 - 48 cm from each other on the carriage. This means that the attachment clamps connect the guide bar of the chain saw at this distance, one clamp being attached to the front part of the guide bar and the other one to the end part of the guide bar next to the body of the chain saw. The attachment clamps clamp the guide bar to secure the chain saw to the carriage of the portable sawmill. The attachment clamps can be for example compressive clamps, or parts that are screwed together to clamp the guide bar on both sides, or a vice.

[0049] According to the invention the portable sawmill comprises a transport mechanism between the carriage and the beam to move the carriage along the beam.

[0050] In other words, the transport mechanism is arranged to move the carriage along the beam between the first end and the second end of the beam. The transport mechanism preferably comprises a handle or a winch provided at the carriage, which can be used to move the carriage along the beam. The transport mechanism also comprises

[0051] The transport mechanism preferably comprises a handle or a winch arranged in connection with the carriage, by means of which the carriage can be moved along the beam. The transport mechanism also comprises a power transmission mechanism provided between the beam and the carriage, and which is operated by the handle or the winch. The power transmission mechanism can be for example a belt arrangement, or a rack and pinion combination which is provided to transmit power between the carriage and the beam. Therefore, a belt or a rack can be arranged to extend along the beam, for example on a side of the beam and a pulley, a pulley wheel or a pinion can be provided in connection with the carriage.

[0052] According to the invention the first end member comprises a first attachment head arranged to connect to a first end of the log, and the second end member comprises a second attachment head arranged to connect to the second end of the log, the first attachment head and the second attachment head extending from the beam such that when the sawmill is connected to the log, the beam rests on the log, and the chain saw connected to the carriage cuts a board from below the first attachment head and the second attachment head between the first end of the log and the second end of the log.

[0053] In other words, once a board has been sawn, i.e. cut, from a log, the portable sawmill is separate from the log and must be connected back to the log to saw a new board from the log. Thus, the chain saw saws the board off from the log from below the attachment points of the first and second attachment heads on the log.

[0054] The advantage of the invention is that a log can be sawn into boards at a wood cutting site without the need to clear the ground for a portable sawmill, but the sawmill can be connected directly and exclusively to the felled tree. Another advantage of the invention is that the portable sawmill is compact enough to be carried around and is easy to assemble when used, for example, at a logging site.

[0055] BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The invention is described in detail by means of specific embodiments with reference to the enclosed drawings, in which

[0057] Figure 1 shows a portable sawmill according to the invention as seen from side;

[0058] Figure 2 shows the portable sawmill shown in figure 1 together with a log;

[0059] Figure 3 shows the portable sawmill shown in figures 1 and 2 in a situation where a board is being sawn from the log;

[0060] Figure 4 shows the portable sawmill shown in figure 3 as seen from top of the portable sawmill, and

[0061] Figure 5 shows the portable sawmill according to the invention as seen from the side together with a log

[0062] DETAILED DESCRIPTION OF THE INVENTION

[0063] Figure 1 shows a portable sawmill 1 according to the invention, which the portable sawmill 1 comprises a beam 10 having a first end 11 and a second end 12, and a first end member 20 and a second end member 30 provided on the beam 10 such that a log 100 can be provided between the end members 20, 30. In this embodiment of the invention the first end member 20 is arranged movably on the beam 10, while the second end member 30 is arranged immovably at the second end 12 of the beam 10. The first end member 20 has a first attachment head 21 and the second end member 30 has a second attachment head 31 between which a log 100 is to be arranged. The portable sawmill 1 is supported on the log 100 through the first and second attachment heads 21, 31. The first attachment head 21 connects to the log at the first end of the log so that the support force is to the longitudinal direction of the log and the second attachment head 31 connects to the log at the second end of the log so that the support force is to the longitudinal direction of the log but on opposite direction that the support force of the first attachment head 21, so that the log is secured between the first attachment head 21 and the second attachment head 31. The first attachment head 21 and the second attachment head 31 thus extend to a direction which is parallel to the longitudinal direction of the beam 10 of the portable sawmill 1 which means that the support force to the log 100 is to the longitudinal direction of the log which is thus parallel to the beam 10. The first end member 20 and the second end member 30 extend from the beam 10 in a transverse direction away from the beam 10 so that the first attachment head 21 of the first end member 20 and the second attachment head 31 of the second end member 30 are preferably arranged at least at the level of the central part of the log. Therefore, the first end member 20 and the second end member 30 are arranged to support the beam 10 to the log 100 also in a radial direction of the log 100. As can be seen in figure 1, the first end member 20 comprises a first arm 25 extending in a transverse direction to the beam 10, and the first attachment head 21 is extending from the first arm 25 towards the log in a parallel direction to the beam 10. The first attachment head 21 is movable in the radial direction of the log away and towards the beam 10 which is achieved in this embodiment of the invention with the first arm 25 and a tube 24, in which the first arm 25 moves in the tube 24, which is arranged in connection with a connecting element 23 in the first end member 20, and through which the first end member 20 is connected to the beam 10.

[0064] The first end member 20 also comprises a first distance meter 22 which extends from the first end member 20 to be placed on the outer surface of the log 100. The first distance meter 22 is provided between the log 100 and the beam 10 and helps defining a constant thickness for the board to be sawn from the log 100. The first distance meter 22 is arranged to extend parallel to the beam 10 and at a distance from the beam 10 so that there is a gap between the beam 10 and the first distance meter 22.

[0065] The portable sawmill 1 also comprises a second end member 30 which in this embodiment of the invention is arranged immovably at the second end 12 of the beam 10. The second end member 30 comprises a corresponding attachment head 31 as the first end member 20 has. The function of the second attachment head 31 is like the first attachment head 21. The first attachment head 21 and the second attachment head 31 press the log 100 between the first end member 20 and the second end member 30 in the longitudinal direction of the log which is a direction parallel to the longitudinal direction of the beam 10. The second attachment head 31 is movable in the radial direction of the log away and towards the beam 10 which is achieved in this embodiment of the invention with the second arm 35 and a tube 34, in which the second arm 35 moves in the tube 34, which is arranged in connection with a connecting element 33 in the second end member 30, and through which the second end member 30 is connected to the second end 12 of the beam 10.

[0066] The second distance meter 32 extends from the second end member 30 parallel to the beam 10 and is placed on the outer surface of the log 100 such that the second distance meter 32 is between the beam 10 and the log 100.

[0067] The portable saw 1 also comprises a carriage 40 connected to the beam 10 and moving along the beam 10 between the first end member 20 and the second end member 30. The carriage 40 comprises attachment clamps 41, which are arranged in the carriage 40 with respect to the longitudinal direction of the beam 10 such that there is at least one attachment clamp on each side of the beam 10. The attachment clamps 41 also extend at least to the side of the beam 10 on which the log 100 is to be placed. The attachment clamps 41 are arranged to connect a chain saw to the portable sawmill 1 such that the guide bar of the chain saw extends transversely to the longitudinal direction of the beam and is positioned between the distance meter 22, 32 and the attachment head 21, 32 in the radial direction of the log. The saw chain of the chain saw is towards the first end of the log when the sawing starts from the first end of the log. The carriage 40 also comprises a handle 42 or a winch for moving the carriage 40 along the beam 10. The beam 10 is provided with a transport mechanism between the carriage 40 and the beam 10 to move the carriage 40 along the beam 10.

[0068] Figure 2 shows the portable sawmill 1 shown in figure 1 together with a log 100. The figure 2 also shows the chain saw 200 connected to the carriage 40. Otherwise, the features presented in figure 2 are the same as presented in figure 1 and are not therefore for the sake of clarity repeated here again.

[0069] The carriage 40 has been moved next to the first end member 20 and sawing of the log 100 has been started. A chain saw 200 has been attached to the attachment clamps 41 and the movement of the carriage 40 has been initiated such that the guide bar 201 comprising the saw chain has protruded into the first end 101 of the log 100. The first distance meter 22 and the second distance meter 32 are arranged on that outer surface of the log 100 which faces the beam 10. The carriage 40 moving along the beam 10 keeps the distance of the chain saw 200 from the beam 10 constant during the sawing, and when the first distance meter 22 and the second distance meter 32 are arranged on the same plane to determine the position of the log to be parallel to the beam 10, the thickness of the board sawn from the log is the same throughout the board.

[0070] Figure 3 shows the portable sawmill 1 during sawing. The carriage 40 is moved from the first end 101 of the log 100 towards the second end 102 of the log 100 and the chain saw 200 has sawn a board having a constant thickness. The features presented in figure 3 are the same as already presented in connection with figures 1 and 2 and therefore are not repeated here again.

[0071] The first attachment head 21 and the second attachment head 31 support the portable sawmill 1 on the log 100 in a longitudinal direction DL of the log 100, and the first arm 25 and the second arm 35 extending from the respective connecting elements 23, 33 in the first end member 20 and the second end member 30 support the portable sawmill 1 in a radial direction DR of the log 100 from the centre of the log 100 towards the beam 10. The radial direction DR of the log 100 is in this context the direction from the centre of the log 100 to the outer surface of the log 100 facing the beam 10. The first attachment head 21 is connected to the first arm 25 and the second attachment head 31 is connected to the second arm 35, which the arms 25, 35 extend transverse to the longitudinal direction of the beam 10 as well as transverse to the first attachment head 21 and the second attachment head 31. The first attachment head 21 and the second attachment head 31 preferably extend parallel to the beam 10.

[0072] Figure 4 shows the portable sawmill 1 shown in figure 3 as seen from top of the portable sawmill 1. The guide bar 201 of the chain saw 200 extends through the log 100 and saws the log 100 in a direction from the first end 101 of the log 100 to the second end 102 of the log 100, i.e. in the longitudinal direction of the log 100. The beam 10 of the portable sawmill 1 extends parallel to the log 100 and is provided with the first end member 20 and the second end member 30. The second end member 30 is provided at the second end 12 of the beam 10 whereas the first end member 20 is provided at a distance from the first end 11 of the beam 10. The first distance meter 22 and the second distance meter 32 are placed on the outer surface of the log 100 on top of the log 100 which is the surface facing towards the beam 10. Figure 4 also shows the connecting elements 23, 33 in connection with the first end member 20 and the second end member 30. The connecting elements 23, 33 connect the end members 20, 30 to the beam 10. The figure 4 also shows that the carriage 40 comprises the attachment clamps 41 on both sides of the beam 10 in the longitudinal direction of the beam 10. The attachment clamps 41 extends at the sides of the log 100 so that the guide bar 201 of the chain saw 200 is connected to the attachment clamps 41. The carriage 40 also comprises a handle 42 which is used to winch the carriage 40 along the beam 10. In this embodiment of the invention the transport mechanism between the carriage 40 and the beam 10 is a belt arrangement. The belt arrangement comprises a belt 43 extending along the side of the beam and connected preferably fixedly to the second end 12 of the beam 10 and adjustably to the first end 11 of the beam 10. The adjustability is achieved in this embodiment of the invention with a ratchet which adjusts the length of the belt and tightens it. The carriage 40 is then moved by winching along the beam 10 using the belt 43 and the handle 42 on the carriage 40.

[0073] Figure 5 shows the portable sawmill 1 together with a log 100. The portable sawmill 1 comprises a beam 10 having a first end 11 and a second end 12, and a first end member 20 and a second end member 30 provided on the beam 10 such that a log 100 can be provided between the end members 20, 30. The first end member 20 and the second end member 30 are either arranged movably or immovably provided on the beam 10. One of the end members 20, 30 can be movably arranged while the other one of the end members 20, 30 can be immovably arranged, or both end members 20, 30 can be movably arranged on the beam 10. The first end member 20 has a first attachment head 21 and the second end member 30 has a second attachment head 31 between which the log 100 is arranged. The first end member 20 comprises fastening means 26 which, in a locked state, fasten the first end member 20 immovably to the beam 10. The second end member 30 also comprises fastening means 36 which, in a locked state, fasten the second end member 30 immovably to the beam 10. When the fastening means 26, 36 are in an open state, the position of the end member 20, 30 relative to the beam 10 can be changed. The first end member 20 is connected to the beam 10 with a connecting element 23 such that the beam 10 extends through the connecting element 23 and the connecting element 23 is movable along the beam 10 to position the first end member 20 relative to the beam 10 in a longitudinal direction of the beam 10. Correspondingly, the second end member 30 is connected to the beam 10 with a connecting element 33 such that the beam 10 extends through the connecting element 33 and the connecting element 33 is movable along the beam 10 to position the second end member 30 relative to the beam 10 in a longitudinal direction of the beam 10.

[0074] The portable sawmill 1 shown in figure 5 is supported on the log 100 by means of the first and second attachment heads 21, 31 and by means gravity while the beam 10 is lying on top of the log 100. In other words, the sawmill stays in place on the log 100 because of the firstand second attachment heads 21, 31 and its own weight, with the beam resting on top of the log 100. The first and second attachment heads 21, 31 secure the sawmill 1 to the log 100 and support the beam 10 to the log 100 while the beam lies on the log 100. The first attachment head 21 connects to the log at the first end 101 of the log 100 so that the support force is to the longitudinal direction of the log 100 and the second attachment head 31 connects to the log at the second end 102 of the log 100 so that the support force is to the longitudinal direction of the log 100 but on opposite direction that the support force of the first attachment head 21, so that the log is secured between the first attachment head 21 and the second attachment head 31. The first attachment head 21 and the second attachment head 31 thus extend to a direction which is parallel to the longitudinal direction of the beam 10 of the portable sawmill 1 which means that the support force to the log 100 is to the longitudinal direction of the log which is thus parallel to the beam 10.

[0075] The first end member 20 and the second end member 30 are arranged to extend from the beam 10 to the side of the beam 10 on which the log 100 is located. However, the first end member 20 and the second end member 30 extend only such that the attachment between the first end attachment head 21 and the log 100 and between the second attachment head 31 and the log 100 remains on the board to be sawn from the log 100. In other words, the thickness of the board to be sawn determines the distance from the beam 10 where the first attachment head 21 and the second attachment head 31 are located. The first end member 20 and the second end member 30 are arranged to support the beam 10 to the log 100 also in radial direction of the log 100 until the board has been sawn. After the board has been sawn, the attachment between the sawmill 1 and the board has to be removed and the portable sawmill 1 has to be reconnected to the log 100 again.

[0076] The portable sawmill 1 also comprises a carriage 40 connected to the beam 10 and moving along the beam 10 between the first end member 20 and the second end member 30. The carriage 40 comprises attachment clamps 41, which are arranged in the carriage 40 with respect to the longitudinal direction of the beam 10 such that there is at least one attachment clamp on each side of the beam 10. The attachment clamps 41 also extend at least to the side of the beam 10 on which the log 100 is to be placed. The attachment clamps 41 are arranged to connect a chain saw 200 to the portable sawmill 1 such that the guide bar 201 of the chain saw extends transversely to the longitudinal direction of the beam. The carriage 40 also comprises a handle 42 or a winch for moving the carriage 40 along the beam 10. The beam 10 is provided with a transport mechanism between the carriage 40 and the beam 10 to move the carriage 40 along the beam 10.

[0077] Figure 5 shows the portable sawmill 1 during sawing. As shown in figure 5 the chain saw 200 is connected to the carriage 40 and the guide bar 201 has sawed the board off the log starting from one end 102 of the log 100. The sawing line extends under the attachment point of the second attachment head 31 so that when the board has been completely sawn from the log 100 the portable sawmill 1 remains in connection with the sawm board.

[0078] The invention has been described above with reference to the examples shown in the figures. However, the invention is in no way restricted to the above examples but may vary within the scope of the claims.

Claims

CLAIMS1. A portable sawmill (1) for sawing logs (100) into sawn timber characterized in that the portable sawmill (1) comprises:- a beam (10) having a first end (11) and a second end (12),- a first end member (20) provided to the beam (10),- a second end member (30) provided to the beam (10), the first end member (20) and the second end member (30) are arranged to receive a log (100) between the first and second end members (20, 30) and to secure the log (100) from its ends to the portable sawmill (1) in a direction parallel to the beam (10), the first end member (20) and the second end member (30) are arranged to support the beam (10) to the log (100) in longitudinal and radial directions of the log (100),- a carriage (40) for connecting a chain saw (200) to the portable sawmill (1), the carriage (40) is movably connected to the beam (10) and arranged to move along the beam (10) between the first end member (20) and the second end member (30).

2. A portable sawmill (1) according to claim 1, characterized in that the first end member (20) is arranged to be movable along the beam (10), the first end member (20) comprises fastening means (26) which, in a locked state, fasten the first end member (20) immovably to the beam (10).

3. A portable sawmill (1) according to claim 1 or 2, characterized in that the first end member (20) comprises a first attachment head (21) arranged to connect to a first end (101) of the log (100).

4. A portable sawmill (1) according to claim 3, characterized in that the first attachment head (21) is movable in the radial direction of the log (100) to adjust its position at the first end (101) of the log (100).

5. A portable sawmill (1) according to any previous, characterized in that the first end member (20) comprises a first distance meter (22) arranged to be placed on the log (100) so as to contact the outermost surface of the log (100) facing the beam (10).

6. A portable sawmill (1) according to any previous claim,characterized in that the first end member (20) is connected to the beam (10) with a connecting element (23) such that the beam (10) extends through the connecting element (23), the connecting element (23) is movable along the beam (10) to position the first end member (20) relative to the beam (10) in a longitudinal direction of the beam (10).

7. A portable sawmill (1) according to claims 3 and 6, characterized in that the first attachment head (21) is movably connected to the connecting element (23) such that the first attachment head (21) is movable in a direction transverse to the longitudinal direction of the beam (10).

8. A portable sawmill (1) according to any previous claim, characterized in that the second end member (30) comprises fastening means (36) which, in a locked state, fasten the second end member (30) immovably to the beam (10), and the second end member (30) is:- connected to the second end (12) of the beam (10) immovably, or- arranged to be movable along the beam (10), when the fastening means (36) are in an open state, to position the second end member (30) relative to the beam (10).

9. A portable sawmill (1) according to any previous claim, characterized in that the second end member (30) comprises a second attachment head (31) arranged to connect to a second end (102) of the log (100).

10. A portable sawmill (1) according to claim 9, characterized in that the second attachment head (31) is movable in the radial direction of the log (100) to adjust its position at the second end (102) of the log (100).

11. A portable sawmill (1) according to any previous claim, characterized in that the second end member (30) comprises a second distance meter (32) arranged to be placed on the log (100) so as to contact the outermost surface of the log (100) facing the beam (10).

12. A portable sawmill (1) according to any previous claim, characterized in that the portable sawmill (1) is arranged to be supported18 solely to the log (100).

13. A portable sawmill (1) according to any previous claim, characterized in that the carriage (40) comprises attachment clamps (41) for connecting the chain saw (200) to the portable sawmill (1).

14. A portable sawmill (1) according to claim 13, characterized in that the attachment clamps (41) are arranged to extend away from the beam (10) so that the chain saw (200) connected to the attachment clamps (41) is between the first end member (20) and the second end member (30).

15. A portable sawmill (1) according to claim 13 or 14, characterized in that the attachment clamps (41) comprise at least a first attachment clamp (41a) and a second attachment clamp (41b) which extend away from the beam (10) on the opposite sides of the beam (10).

16. A portable sawmill (1) according to claim any of claims 13-15, characterized in that the attachment clamps (41) are adjustable so that a distance of the chain saw (200) relative to the beam (10) is adjustable.

17. A portable sawmill (1) according to any previous claim, characterized in that the portable sawmill (1) comprises a transport mechanism between the carriage (40) and the beam (10) to move the carriage (40) along the beam (10).

18. A portable sawmill (1) according to claim 1, characterized in that the first end member (20) comprises a first attachment head (21) arranged to connect to a first end (101) of the log (100), and the second end member (30) comprises a second attachment head (31) arranged to connect to the second end (102) of the log (100), the first attachment head (21) and the second attachment head (31) extending from the beam (10) such that when the sawmill (1) is connected to the log (100), the beam (10) rests on the log (100), and the chain saw (200) connected to the carriage (40) saws a board from below the first attachment head (21) and the second attachment head (31) between the first end (101) of the log (100) and the second end (102) of the log (100).

Images