Circular saw for sawing logs with a two-part rotatable saw drum, the upper part of which is slidably mounted on a driven rotating shaft.

Abstract

Device (100) for sawing logs to a predetermined length, comprising a rotatably mounted saw drum (110) which is non-rotatably connected to a driven rotating shaft (105), wherein the saw drum (110) has a plurality of feed slots (120) for feeding logs to be sawn, wherein the saw drum (110) together with each of the feed slots (120) is divided into two parts and an upper part of a feed slot (120) is arranged in an upper saw drum part (111) and a lower part of a corresponding feed slot (120) is arranged in a lower saw drum part (112) and the saw blade (131) of a circular saw (130) partially engages in a gap between the upper saw drum part (111) and a corresponding lower saw drum part (112), wherein by rotation of the saw drum (110) each feed slot (120) is brought into the effective area of ​​the saw blade (131) of the circular saw (130) is reached, characterized by that the rotating shaft (105) is arranged at an angle of 30° to 60° to the horizontal, and the upper saw drum part (111) has a lower stop (107) on its lower side, which is supported against an upper stop on the upper side of the lower saw drum part (112) forming the gap, wherein the upper saw drum part (111) is mounted so as to be displaceable upwards along the rotating shaft (105) against the force of gravity and the displacement of the upper saw drum part (111) is limited by an upper stop (106) of the rotating shaft (105), and the lower saw drum part (112) is mounted so as not to be displaceable along the rotating shaft (105), wherein, in the event of a larger saw chip falling in and becoming trapped between the upper saw drum part (111) and the saw blade (131) of the circular saw (130), the action of the saw chip causes a lower limiting edge of the upper saw drum part (111) to be moved upwards along the rotating shaft (105) against the force of gravity, thereby increasing the gap between the saw blade (131) of the circular saw (130) and the lower limiting edge of the upper saw drum part (111) and automatically freeing the saw chip from its jammed position.

Description

[0001] The invention relates to a device for sawing logs to a predetermined length, with a rotatably mounted saw drum which is non-rotatably connected to a driven rotating shaft, wherein the saw drum has a plurality of feed slots for feeding logs to be sawn, wherein the saw drum together with each of the feed slots is divided into two parts and an upper part of a feed slot is arranged in an upper part of the saw drum and a lower part of a respective feed slot is arranged in a lower part of the saw drum and the saw blade of a circular saw partially engages in a gap between the upper part of the saw drum and a respective lower part of the saw drum, wherein by rotation of the saw drum each feed slot enters the working area of ​​the saw blade of the circular saw.

[0002] Devices of the type mentioned above are known in the prior art in a multitude of different embodiments. However, the known devices have the disadvantage of being prone to malfunctions during operation, particularly because larger sawdust fragments, which are regularly generated unintentionally during sawing, get caught between the circular saw blade and a lower limiting edge of the upper part of the saw drum, thereby obstructing the rotation of the saw blade. In such a case, operation must be stopped briefly to remove the sawdust fragment by hand. Depending on the nature of the wood being sawn, this can significantly disrupt and prolong the sawing process.

[0003] German patent DE 823 037 B discloses a sawing machine for sawing elongated pieces of wood, which are fed to the saw by means of an inclined, rotating drum, wherein pipes of circular, oval or other cross-section adapted to the shape of the pieces to be sawn are arranged on a large diameter in the drum, wherein furthermore two coaxial and co-rotating discs are provided downstream of the drum, which are provided with openings corresponding to the pipes in the drum and located in their extensions and between which the saw blade of a circular saw is accommodated, the shaft of which runs parallel to the drum shaft, and furthermore a spring-loaded, flexible stop disc is provided at the lower end of the drum shaft to prevent any jamming during the sawing process.against which the wood pieces rest after exiting the drum and passing through the discs, before they enter the area of ​​the saw blade as the drum rotates.

[0004] From the publication DE 296 07 119 U1, a sawing device for sawing pre-split logs and round timber is known, wherein in the sawing machine equipped with a circular saw the wood (H) can be fed to the saw blade by means of a drum, and the saw drum is arranged at an inclination of 30 - 70° so that the wood moves downwards by gravity and the rotational movement of the drum, whereby an adjustable base plate forms a length stop.

[0005] The publication EP 705 937 A1 discloses a machine for sawing logs, comprising a frame supporting a saw equipped with a motorized drive mechanism, means for receiving at least one log arranged upstream of the saw, wherein these means are movable at least between a rest position and a sawing position, and means for removing the cut log sections, wherein a rotating carrier of the loading device comprises a movable drum formed by at least three elements arranged one behind the other and connected to each other, namely a first element that receives logs, a second element that performs a cutting action, and a third, telescopically constructed element.

[0006] From the publication EP 3 045 248 A2, a cutting machine for elongated elements is known, comprising a drum body containing one or more channels, a saw that interrupts the channels to cut an elongated element housed in the respective channel while the drum body rotates in one direction, wherein the saw and the drum body each have an element radially inside the channel to connect the drum body and the motor to the rotation.

[0007] From the publication DE 10 2017 113 956 A1, a device for sawing logs to a predetermined length is known, comprising a feed drum rotatably mounted about a rotational axis and having a plurality of feed shafts delimited by a shaft bottom for introducing logs to be sawn, wherein, by rotation of the feed drum, each feed shaft enters the working area of ​​a stationary circular saw, and with an outlet opening arranged in the conveying path behind the circular saw for transporting sawn logs, wherein each feed shaft is designed in three parts: a first shaft part arranged upstream of the circular saw in the direction of the log feed, a second shaft part into which the saw blade of the circular saw engages, and a third shaft part arranged downstream of the circular saw, wherein the first shaft part is formed by a closed shaft wall and has an opening for ejecting sawn logs.the second shaft section is formed by at least one web connecting the first shaft section to the third shaft section, which separates the first shaft section from the third shaft section in order to create a space for the engagement of the circular saw blade.

[0008] The publication EP 3 357 619 A1 discloses a machine for cutting firewood, with a cutting station comprising a rotating saw disc and a drum rotatable about a downwardly inclined axis and provided with tubular axial guides for the gravity feed to a cutting station, wherein the rotating saw disc is suitable for intercepting the log sections transversely and cutting logs of predetermined length, wherein a first device is provided for moving the saw disc between a raised rest position and a lowered working position, and a second device is provided for controlling the rotation of the drum, as well as control means for coordinating the movement of the saw disc with the movement of the radial element for clamping the log section during cutting, and for coordinating the movement of the saw disc with the movement of the axial element for stopping a log section.

[0009] German patent application DE 20 2015 106 326 U1 discloses a device for sawing logs to a predetermined length, comprising a feed drum rotatably mounted about a central axis and a plurality of feed shafts delimited by a shaft bottom for introducing logs to be sawn, wherein by rotating the feed drum each feed shaft can be brought into the working area of ​​a stationary circular saw, and a discharge device arranged in the conveying path behind the circular saw for transporting sawn logs, wherein the feed drum contains a plurality of spaced-apart segments separated from each other in the direction of the central axis by slots of predetermined width, wherein a main segment is arranged in front of the circular saw in the feed direction of the logs and one or more additional segments are arranged behind the circular saw in the feed direction of the logs, wherein the width of the slots is dimensioned.to accommodate a shaft floor panel that can be detachably placed perpendicular to the central axis and forms the shaft floor, which can alternatively be placed behind one of the additional segments to create a shaft depth of variable length.

[0010] The object of the invention is to provide a device for sawing logs in which operational reliability can be increased compared to known devices and susceptibility to malfunctions can be reduced accordingly.

[0011] For a device of the type mentioned above, this problem is solved according to the invention in that the rotating shaft is arranged at an angle of 30° to 60° to the horizontal, and the upper saw drum part has a lower stop on its lower side which is supported against an upper stop on the upper side of the lower saw drum part, forming the gap, wherein the upper saw drum part is mounted so as to be displaceable upwards along the rotating shaft against the force of gravity and a displacement of the upper saw drum part is limited by means of an upper stop of the rotating shaft, and the lower saw drum part is mounted so as not to be displaceable along the rotating shaft.and in the event of a larger saw chip becoming lodged and jammed between the upper part of the saw drum and the saw blade of the circular saw, the action of the saw chip causes a lower limiting edge of the upper part of the saw drum to be moved upwards along the rotating shaft against the force of gravity, thereby increasing the gap between the saw blade of the circular saw and the lower limiting edge of the upper part of the saw drum and automatically freeing the saw chip from its jammed position.

[0012] Preferred embodiments of the invention are the subject of the dependent claims, the elements of which serve to further improve the solution approach to the problem underlying the invention.

[0013] In the device according to the invention, the combination of features of the characterizing part of claim 1 in conjunction with the features of its preamble ensures that, in the event of a sawdust chip falling in and becoming trapped between the saw blade of the circular saw and a lower limiting edge of the upper saw drum part, the upper saw drum part is moved upwards along the rotating shaft by the action of the sawdust chip, thereby increasing the gap between the saw blade of the circular saw and the lower limiting edge of the upper saw drum part and automatically releasing the sawdust chip from its clamping position.

[0014] According to a first preferred embodiment of the device according to the invention, the rotating shaft projects a defined extent beyond the upper edge of the upper saw drum part, and displacement of the upper saw drum part along the rotating shaft is limited by means of an upper stop of the rotating shaft.

[0015] According to another preferred embodiment of the device according to the invention, a dirt-repellent bellows is arranged between the upper edge of the upper saw drum part and the upper stop of the rotating shaft to prevent the accumulation of contaminants around the rotating shaft.

[0016] Alternatively or additionally, a resilient elastic damping element can be inserted between the upper edge of the upper saw drum part and the upper stop of the rotating shaft to partially absorb the kinetic energy of the upper saw drum part caused by the action of a larger saw chip in the direction of the upper stop.

[0017] The dirt-repellent bellows or the elastic damping element can, for example, be formed from a rubber bellows.

[0018] Furthermore, the lower stop for supporting the upper saw drum part is preferably formed by one or more spacer discs that are inserted between the lower saw drum part and the upper saw drum part.

[0019] The rotating shaft is further preferably formed by a hexagonal shaft, which is guided through corresponding respective hollow profiles in the upper saw drum part and the lower saw drum part.

[0020] According to another preferred embodiment of the device according to the invention, the rotating shaft can be driven by a motor device which drives the rotating shaft at an adjustable constant speed.

[0021] The device according to the invention is explained below with reference to a preferred embodiment, which is illustrated in the figures of the drawing. This shows: Fig. 1 a preferred embodiment of the device according to the invention in a themed view from an oblique top view; Fig. 2 in Fig. 1. Preferred embodiment of the device according to the invention shown in a themed side view in a basic state; Fig. 3 in Fig. 1. A preferred embodiment of the device according to the invention is shown in a themed side view in a raised, expanded state.

[0022] The in the Fig. 1, Fig. 2 to Fig. The device 100 shown in Figure 3 is designed for sawing logs to a predetermined length and includes a rotatably mounted saw drum 110, which is non-rotatably connected to a driven rotating shaft 105, and the saw drum 110 has a plurality of feed shafts 120 for feeding logs to be sawn, wherein the saw drum 110 together with each of the feed shafts 120 is divided into two parts and an upper part of a feed shaft 120 is arranged in an upper saw drum part 111 and a lower part of a respective feed shaft 120 is arranged in a lower saw drum part 112.

[0023] For a sawing operation, the saw blade 131 of a circular saw 130 partially engages in a gap between the upper saw drum part 111 and a corresponding lower saw drum part 112, whereby, by rotation of the saw drum 110, an insertion shaft 120 enters the working area of ​​the saw blade 131 of the circular saw 130.

[0024] The upper saw drum part 111, supported on a lower stop 107, is slidably mounted along the rotating shaft 105.

[0025] The rotating shaft 105 projects a defined extent beyond the upper edge of the upper saw drum part 111, wherein a displacement of the upper saw drum part 111 along the rotating shaft 105 is limited by means of an upper stop 106 of the rotating shaft 105.

[0026] A dirt-repellent bellows 108 is arranged between the upper edge of the upper saw drum part 111 and the upper stop 106 of the rotating shaft 105 to prevent the accumulation of contaminants around the rotating shaft 105.

[0027] The lower stop 107 for supporting the upper saw drum part 111 is formed by a plurality of spacer discs which are attached between the lower saw drum part 112 and the upper saw drum part 111.

[0028] The rotating shaft 105 is arranged at an angle of approximately 45° to the horizontal.

[0029] Furthermore, the rotating shaft 105 is formed by a hexagonal shaft which is guided by corresponding respective hollow profiles in the upper saw drum part 111 and the lower saw drum part 112.

[0030] The rotary shaft 105 can be driven by a hydraulically driven motor device (not shown), which drives the rotary shaft 105 at an adjustable constant rotational speed.

[0031] The embodiment of the invention described above serves only the purpose of a better understanding of the teaching of the invention specified by the claims, which as such is not limited by the embodiment. Reference symbol list 100 Device 105 Rotational shaft 106 upper stop 107 lower limit 108 Bellows / Damping element 110 saw drum 111 upper saw drum part 112 lower saw drum part 120 Inlet shaft 130 circular saw 131 saw blade

Claims

Device (100) for sawing logs to a predetermined length, comprising a rotatably mounted saw drum (110) which is non-rotatably connected to a driven rotating shaft (105), wherein the saw drum (110) has a plurality of feed slots (120) for feeding logs to be sawn, wherein the saw drum (110) together with each of the feed slots (120) is divided into two parts and an upper part of a feed slot (120) is arranged in an upper saw drum part (111) and a lower part of a corresponding feed slot (120) is arranged in a lower saw drum part (112) and the saw blade (131) of a circular saw (130) partially engages in a gap between the upper saw drum part (111) and a corresponding lower saw drum part (112), wherein by rotation of the saw drum (110) each feed slot (120) is brought into the effective area of ​​the saw blade (131) of the circular saw (130) is thereby characterized,that the rotating shaft (105) is arranged at an angle of 30° to 60° to the horizontal, and the upper saw drum part (111) has a lower stop (107) on its lower side, which is supported against an upper stop on the upper side of the lower saw drum part (112) forming the gap, wherein the upper saw drum part (111) is mounted so as to be displaceable upwards along the rotating shaft (105) against the force of gravity, and a displacement of the upper saw drum part (111) is limited by means of an upper stop (106) of the rotating shaft (105), and the lower saw drum part (112) is mounted so as not to be displaceable along the rotating shaft (105),wherein, in the event of a larger saw chip falling in and becoming jammed between the upper saw drum part (111) and the saw blade (131) of the circular saw (130), the action of the saw chip causes a lower limiting edge of the upper saw drum part (111) to move upwards along the rotating shaft (105) against the force of gravity, thereby increasing the gap between the saw blade (131) of the circular saw (130) and the lower limiting edge of the upper saw drum part (111) and automatically releasing the saw chip from its jammed position. Device according to claim 1, characterized in that the rotating shaft (105) projects a defined extent beyond the upper edge of the upper saw drum part (111) and the displacement of the upper saw drum part (111) along the rotating shaft (105) is limited by means of the upper stop (106) of the rotating shaft (105). Device according to claim 2, characterized in that a dirt-repellent bellows (108) is arranged between the upper edge of the upper saw drum part (111) and at the upper stop (106) of the rotating shaft (105) to prevent the accumulation of contaminants around the rotating shaft (105). Device according to claim 2 or claim 3, characterized in that a resilient elastic damping element (108) is inserted between the upper edge of the upper saw drum part (111) and the upper stop (106) of the rotating shaft (105) for the partial absorption of the kinetic energy of the upper saw drum part (111) caused by the action of a larger saw chip in the direction of the upper stop. Device according to claim 4, characterized in that the elastic damping element (108) is formed by a rubber bellows. Device according to one of the preceding claims, characterized in that the lower stop (107) on the lower side of the upper saw drum part (111) for supporting the upper saw drum part (111) is formed by one or more spacer discs which are attached between the lower saw drum part (112) and the upper saw drum part (111). Device according to one of the preceding claims, characterized in that the rotating shaft (105) is formed by a hexagonal shaft which is guided by corresponding respective hollow profiles in the upper saw drum part (111) and the lower saw drum part (112). Device according to one of the preceding claims, characterized in that the rotating shaft (105) is driven by a motor device which drives the rotating shaft (105) at an adjustable constant speed.

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