METHOD AND DEVICE FOR HANDLING ELONGATED TIMBER ELEMENTS

Abstract: In a method for handling elongated timber elements, timber elements of essentially the same length are laid down so as to form a stack (9, 10) of timber elements, which are then removed from this stack. A plurality of layers of timber elements which are parallel to one another and arranged side by side, which layers are imparted a width which is slightly smaller than the length of the timber elements, are arranged in such a manner that they form a stack (9, 10) of layers of timber elements, which layers are positioned in a centred manner on one another, the layers being rotated alternately by 90 DEG in relation to one another. A device for implementing this method has a gripping means (16), which can be raised and lowered and can be rotated about a vertical axis, and which has two parallel bearing rails (18) which can be moved towards and away from one another into a bearing position and, respectively, a free position. The bearing rails (18) are arranged so as in their bearing position to bear a layer of timber elements which are parallel to one another and arranged side by side at the ends of the timber elements, and in their free position to set this layer down on a stack (9) of timber elements in the course of construction or on a conveyor (3).

Description: METHOD AND DEVICE FOR HANDLING ELONGATED TIMBER ELEMENTS Technical Field The present invention relates to a method for handling elongated timber elements, such as stacking sticks, m which method timber elements of essentially the same length are laid down so as to form a stack of timber elements, which are then removed from this stack. The invention also relates to a device for implementing this method. Background of the Invention In sawmills, sawn timber is piled m stacks which contain a plurality of layers of timber. Between these layers, stacking sticks are positioned at right angles to the longitudinal direction of the timber, especially m order to facilitate drying of the timber. For further processing of the timber m the sawmill, the timber is removed from the stacks, the sticks then being taken for reuse m new timber stacks. This reuse of stacking sticks nowadays requires handling which is rather complicated and time-consuming and takes up a great deal of space. Summary of the Invention The object of the present invention is therefore m particular to provide a method and a device which make it possible to eliminate or at least considerably reduce these disadvantages and thus simplify this handling of sticks m a sawmill, and more generally to provide a method and a device which make it possible to handle elongated timber elements of any type m a simple and compact manner . According to the present invention, this object is achieved by a method of the type indicated m the introduction, which is characterised m that a plurality of layers of timber elements which are parallel to one another and arranged side by side, which layers are each imparted a width which is slightly smaller than the length of the timber elements, are arranged m such a manner that they form a stack of layers of timber elements, which layers are positioned m an essentially centred manner on one another, the layers being rotated alternately by 90° m relation to one another. The timber elements are preferably laid down and removed layer by layer. In the construction of a stack, the layers are suit- ably added from above and, on removal from a stack, the layers are also suitably removed from above. According to the present invention, the object is also achieved by a device for implementing this method, which device is characterised by a gripping means, which can be raised and lowered and can be rotated about an essentially vertical axis, with two parallel bearing rails which can be moved towards and away from one another into a bearing position and, respectively, a free position, are arranged so as, when a stack is being constructed, in their bearing position to receive a layer of timber elements which are parallel to one another and arranged side by side and to bear this layer at the ends of the timber elements, and m their free position to set this layer down on a top layer of timber elements which are parallel to one another and arranged side by side m a stack of timber elements m the course of construction, doing so with the gripping means m such a rotary position that the first-mentioned layer is rotated by 90° m relation to said top layer, and are furthermore arranged so as, when timber elements are being removed from such a stack of timber elements, while moving from their free position to their bearing position to be inserted a distance under a layer of timber elements m the stack m order, on subsequent upward movement, to bear this layer at the ends of the timber elements forming it. In a preferred embodiment, the device has stay means which are arranged so as, during removal of timber ele- ments from the stack, to retain the underlying layer of timber elements which is located closest below that layer of timber elements under which the bearing rails are inserted a distance, doing so by being brought to bear against the top side of this underlying layer at the ends of the timber elements forming it. Brief Description of the Drawings The invention will now be described m greater detail with reference to the accompanying drawings, m which: Fig. 1 is a side view and shows an installation, provided with a device according to the invention, the device being shown m a stick-receiving position; Fig. 2 shows the installation m the position shown m Fig. 1 from above, the device according to the invention being shown m section along the line II-II m Fig. 1; Fig. 3 is a side view corresponding to Fig. 1 but shows the device according to the invention m a posi- tion m which it has received a layer of sticks; Fig. 4 shows the installation m the position shown m Fig. 3 from above, the device according to the invention being shown m section along the line IV-IV m Fig. 3; Fig. 5 is a side view corresponding to Figs 1 and 3 but shows the device according to the invention in a lowered, setting-down position rotated by 90° m relation to the position m Figs 1 and 3; Fig. 6 shows the installation m the setting-down position shown m Fig. 5 from above, the device according to the invention being shown m section along the line Fig. 7 is a side view corresponding to Fig. 1 but shows the device according to the invention m a starting position for removal of a layer of sticks from a stack; Fig. 8 shows the installation in the starting position shown m Fig. 7 from above, the device according to the invention being shown m section along the line VIII-VIII m Fig. 7 ; Fig. 9 is a partial view and shows a bearing rail on a larger scale, the bearing rail being shown m a free position; Fig. 10 corresponds to Fig. 9 but shows the bearing rail m a bearing position; F g. 11 is a partial view and shows, m the direction of the arrow XI m Fig. 7, a stay rail on a larger scale, the stay rail being shown m an inactive position; Fig. 12 corresponds to Fig. 11 but shows the stay rail m an active position; Fig. 13 is a side view corresponding to Fig. 7 but shows the device according to the invention m a raised, feed-out position rotated by 90° m relation to the position m Fig. 7 ; Fig. 14 shows the installation m the feed-out position shown m Fig. 13 from above, the device according to the invention being shown m section along the line XIV-XIV in Fig. 13; Fig. 15 is a side view corresponding to Figs 7 and 13 but shows the device according to the invention m a position m which it has delivered the layer removed from the stack, and Fig. 16 shows the installation m the position shown m Fig. 15 from above, the device according to the invention being shown m section along the l ne XVI -XVI m Fig. 15. Description of a Preferred Embodiment The installation shown m the drawings is intended m particular for handling stacking sticks and is also described below with regard to this handling. It should nevertheless be understood that the installation can also be used for handling elongated timber elements of essen- tially the same length of any type. The installation shown m the drawings has a stand 1, a device 2 according to the invention supported by the stand 1, an endless, upper conveyor 3, which extends up to the device 2 m the upper part of the stand, and an endless, lower conveyor 4, which extends into the stand 1 m the lower part thereof . The stand 1 consists of four corner posts 5 and a square frame which is supported at the upper ends of these and of which, for the sake of clarity, only two opposite sides m the form of I-beams 6 are shown m the drawings . The upper conveyor 3 consists of two horizontal conveyor chains 7 arranged side by side, which are arranged so as to feed sets of sticks of essentially the same length to the device 2 and the mutual spacing of which is considerably smaller than the length of the sticks (see Fig. 2) . Each set 8 of sticks fed consists here of a layer of sticks which are parallel to one another and positioned next to one another. The width of the layer or set 8, that is to say its extent m the longitudinal direction of the conveyor 3, is somewhat smaller than the length of the sticks (see Fig. 2) . The device 2 is used m order to construct a stack of a plurality of such fed layers or sets 8 m a manner described m greater detail below. A stack 9 m the course of construction is shown inside the stand 1 m Figs 1-6, and a finished stack 10 is shown fed out into a position outside the stand 1. Both the stack 9 and the stack 10 are supported by the lower conveyor 4. The lower conveyor 4 consists of two horizontal conveyor chains 11 arranged side by side, which are arranged so as to support a stack 9 m the course of construction inside the stand 1 and to convey the finished stack 10 out from the stand. The mutual spacing of the conveyor chains 11 is considerably smaller than the length of the sticks (see Fig. 2) . The finished stack 10 consists of a plurality of layers, positioned m an essentially centred manner on one another, of sticks which are parallel to one another and positioned next to one another, where each layer corresponds to a set 8 of sticks fed on the upper conveyor 3. The layers m the finished stack 10 are, like the layers m the stack 9 m the course of construction, rotated alternately by 90° m relation to one another. As the width of each layer is somewhat smaller than the length of the sticks, each layer projects m its longitudinal direction, that is to say the longitudinal direction of the sticks, slightly beyond the layer located closest above and/or below the layer, which means that each layer m the stack is easily grippable. The device 2 has a chassis 12 which, seen from above, is essentially H-shaped and the two H-legs of which bear a wheel 13 at each of their ends. The wheels 13 rest on the two I-beams 6 of the stand frame and m this way support the device 2 on the stand 1. In the embodiment shown, the carriage formed by the H-shaped chassis 12 and the wheels 13 is fixed on the stand 1, because the upper frame of the stand, as mentioned, is square. In an alternative embodiment, this frame is instead of such a rectangular shape that the I-beams 6 constitute the long sides of the frame, which provides space for moving the carriage along the I-beams 6. Such an embodiment is used, for example, when the mstalla- tion has two conveyors 3 arranged side by side and two conveyors 4 arranged side by side, and one and the same device 2 serves both pairs of conveyors 3 , 4. The device 2 also has a vertical column 15 which is mounted in a bearing 14 m the H-crossbar 12a of the chassis 12 and can be both rotated about its vertical axis and raised and lowered by means which are not shown m greater detail. The column 15 supports a framework 16, which is essentially H-shaped seen from above, and is at its lower end rigidly connected to the H-crossbar 16a m the centre thereof. The two H-legs 16b of the framework 16 extend, m the receiving position of the device 2 shown m Figs 1 and 2, at right angles to the H-legs of the chassis 12, that is to say parallel to the upper conveyor 3. The H-crossbar 16a of the framework 16 consists of a rectangular tube which accommodates a cylinder arrange - ment with two piston rods 17 which project a distance from their respective end of the H-crossbar 16a. Each piston rod 17 is, at its projecting end, rigidly connected to a cross-sectionally L-shaped bearing rail 18 which is parallel to the H-legs 16b. The bearing rails 18, which, as shown in greater detail in Figs 9 and 10, have a vertical L-leg and a horizontal, inwardly directed L-leg, can be moved, by means of the cylinder arrangement and the piston rods 17, between a retracted bearing position (see in particular Figs 2, 4, 10, 14 and 16), in which the spacing between the inner ends of the horizontal L-legs of the two bearing rails 18 is smaller than the length of the sticks, and an extended free position (see in particular Figs 5, 6, 7, 8 and 9) , in which this spacing is greater than the length of the sticks. Each of the two H-legs 16b of the framework 16 bears at each end a cylinder assembly 19. The cylinder assemblies 19 at one end of the H-legs 16b bear a stay means in the form of a horizontal bar 20, and the cylinder assemblies 19 at the other end of the H-legs 16b bear a stay means which is also in the form of a horizontal bar 20. The two bars 20 extend at right angles to the H-legs 16b and thus also at right angles to the bearing bars 18. The spacing between the bars 20 is greater than the width of the stick set 8 but smaller than the length of the sticks (see Figs 11 and 12) . The bars 20 can, by means of the cylinder assemblies 19, be moved vertically between an upper, inactive position (Fig. 11) and a lower, active position (Fig. 12) . In Figs 1 and 2, the device 2 is shown in its receiving position, in which, as mentioned, the two H-legs 16b of the framework 16 extend parallel to the upper conveyor 3. In the receiving position, the frame- work 16 is located at such a height that the horizontal L-legs of the bearing rails 18 are located at the same level as the chains 7 m the upper strand of the conveyor 3. The bearing rails 18 are here located m their bearing position. When the device 2 is m the receiving position shown, the set 8 of sticks fed is transferred from the conveyor 3 to the bearing rails 18 either by means of the chains 7, a pusher (not shown) or some other suitable arrangement. A new set 8' of sticks is then fed to the device 2 (see Figs 5 and 6) . The framework 16, now bearing the set 8, is lowered to the pile 9, that is to say the stack m the course of construction. As the sticks m the set 8 are parallel to the sticks m the top layer m the pile 9 (cf. Figs 2 and 4) , the framework 16 is rotated by 90° during its downward movement, so that the sticks m the set 8 are at right angles to the sticks m this top layer when the framework 16 reaches the pile 9. In this position, the downward movement of the framework 16 is stopped, where- upon the bearing rails 18 are, by means of the cylinder arrangement and its piston rods 17, moved into their free position and thus lay the set 8 on the pile 9 (see Figs 5 and 6) . The framework 16 is then returned to its upper position according to Figs 1 and 2, being rotated by 90° during its upward movement. During this movement, the bearing rails 18 are, by means of the cylinder arrangement and its piston rods 17, returned to their bearing position. When the device 2 is again m the receiving position, the set 8' of sticks is transferred from the conveyor 3 to the bearing rails 18, whereupon the cycle described above is repeated with the sole difference that no rotation of the framework 16 takes place, because the sticks m the set 8' are at right angles to the sticks m the set 8 most recently put down During the laying down of stick layers for the construction of a stack, the stay bars 20 are m their inactive position throughout the cycle. When sticks are to be removed layer by layer from a stack or, as shown m Figs 7, 8 and 13-16, from a pile 9, the cycle starts with the device 2 m the starting position shown m Figs 7 and 8, which corresponds to the setting-down position of the device shown m Figs 5 and 6. The bearing rails 18 are, by means of the cylinder arrangement and its piston rods 17, moved from the free position shown m Fig. 9 into the bearing position shown m Fig. 10, so that their horizontal L-legs are inserted a distance under the top layer 21 at the ends of the sticks. The stay bars 20 are, by means of the cylinder assemblies 19, moved from their upper, inactive position (Fig. 11) into their lower, active position (Fig. 12), m which they bear against the next highest layer 22 m the pile 9 at the ends of the sticks. The framework 16 is then raised and lifts the top layer 21 away from the pile 9. The cylinder assemblies 19 function as springs and, via the stay bars 20, press the next highest layer 22 against the pile 9, so that it does not accompany the top layer 21 upwards, for example as a result of the two layers 21 and 22 being stuck together by resin m between. The framework 16 is raised into its upper position, m which the horizontal L-legs of the bearing rails 18 are located at the same level as the chains 7 m the upper strand of the conveyor 3. As the sticks in the layer 21 now borne by the bearing rails 18 are parallel to the conveyor 3 (see Fig. 8), the framework 16 is rotated by 90° during its upward movement, so that these sticks are at right angles to the conveyor 3 when the framework 16 reaches the upper position (see Figs 13 and 14) . When the framework 16 has reached its upper position, the device 2 is m a feed-out position (Figs 15 and 16) , which corresponds to the stick-receiv- mg position shown m Figs 1-4. When the device 2 is m the feed-out position, the layer 21 borne by the framework 16 is transferred from the bearing rails 18 to the conveyor 3 (see Figs 15 and 16) by means of a pusher (not shown) or some other suitable arrangement . The framework 16 is then returned to a lower position, m which the horizontal L-legs of the bearing rails 18 are located at a level immediately below the layer 22 m the pile 9. During the downward movement of the framework 16, the bearing rails 18 are, by means of the cylinder arrangement and its piston rods 17, moved into their free position. When the framework 16 has reached this lower position, the device 2 is again located m a starting position. The cycle described above is repeated with the sole difference that no rotation of the framework 16 takes place, because the sticks m the layer 22 are at right angles to the conveyor 3. By means of the laying down of sticks layer by layer described above, a stack 10 of sticks is obtained, in which the layers are positioned m an essentially centred manner on one another and are rotated alternately by 90° m relation to one another. It should be noted that each "layer", such as m the procedure described, does not necessarily consist of only one ply of sticks. Here, "layer" means one or more plies of sticks, where the sticks in these plies are oriented in one and the same direction. In the above description, it is stated that the sticks are of essentially the same length. It should be understood that the length variation which can be permitted m one and the same layer is determined by the bearing rails 18 m that the maximum stick length is equal to the spacing between the vertical L-legs of the bearing rails 18 when the bearing rails are located m their bearing position, and the minimum stick length is equal to the spacing between the vertical L-leg of one bearing rail 18 and the free, inner end of the horizontal L-leg of the other bearing rail 18 when the bearing rails 18 are located in their bearing position, that is to say that the maximum length variation is equal to the length of a horizontal L-leg. It should also be understood that the width of the layer or the set 8, 8' in the case of such a length variation is determined by the minimum stick length.

Claims: CLAIMS 1. A method for handling elongated timber elements, such as stacking sticks, m which method timber elements of essentially the same length are laid down so as to form a stack (9, 10) of timber elements, which are then removed from this stack, c h a r a c t e r i s e d m that a plurality of layers of timber elements which are parallel to one another and arranged side by side, which layers are each imparted a width which is slightly smaller than the length of the timber elements, are arranged m such a manner that they form a stack (9, 10) of layers of timber elements, which layers are position- ed m an essentially centred manner on one another, the layers being rotated alternately by 90° m relation to one another. 2. A method according to claim 1, c h a r a c t e r i s e d m that the timber elements are both laid down and removed layer by layer. 3. A method according to claim 2, c h a r a c t e r i s e d m that, m the construction of a stack (9, 10) , the layers are added from above, and m that, on removal from a stack, the layers are also removed from above. 4. A device for implementing the method according to claim 1, 2 or 3, c h a r a c t e r i s e d by a gripping means (16) , which can be raised and lowered and can be rotated about an essentially vertical axis, with two parallel bearing rails (18) which can be moved towards and away from one another into a bearing position and, respectively, a free position, are arranged so as, when a stack (9, 10) is being constructed, m their bearing position to receive a layer (8, 8') of timber elements which are parallel to one another and arranged side by side and to bear this layer at the ends of the timber elements, and m their free position to set this layer down on a top layer of timber elements which are parallel to one another and arranged side by side m a stack (9) of timber elements m the course of construction, doing so with the gripping means m such a rotary position that the first-mentioned layer is rotated by 90° m relation to said top layer, and are furthermore arranged so as, when timber elements are being removed from such a stack of timber elements, while moving from their free position to their bearing position to be inserted a distance under a layer of timber elements m the stack m order, on subsequent upward movement, to bear this layer at the ends of the timber elements forming it. 5. A device according to claim 4, c h a r a c t e r i s e d by stay means (20) which are arranged so as, during removal of timber elements from the stack (9) , to retain the underlying layer (22) of timber elements which is located closest below that layer (21) of timber elements under which the bearing rails (18) are inserted a distance, doing so by being brought to bear against the top side of this underlying layer (22) at the ends of the timber elements forming it.

Inventors: GUNNARSSON CENNETH, GUNNARSSON, CENNETH
Applicants: GUNNARSSON CENNETH, GUNNARSSONS VERKST S AB C, C. GUNNARSSONS VERKSTADS AB, GUNNARSSON, CENNETH
Application year: 2001
Main classification: B27B31
IPC codes: B65G57