AN APPARATUS FOR STACKING ELONGATED ITEMS

Abstract: An apparatus for stacking pipes or similar items of round or angular cross-section to form an angular-section stack, the apparatus comprising a stacking table (2) provided with a raising and lowering mechanism, the support surfaces of the table in part corresponding to the shape of the stack to be made, and an inclined feeding plane (4), which is parallel to one side of the stack. The feeding plane (4) constitutes an extension of the support surface of the stacking table (2) at the beginning of the stacking and, respectively, an extension of the lower side of the top layer of items as the stacking progresses. Above the feeding plane (4) there is, parallel to the feeding plane, an upper guide (6), which keeps the arriving flow of items in a single layer, and at the end of the feeding layer there is, adjacent to the stack being formed, a movable edge guide (5) which is synchronized with the movement of the stacking table and can be actuated to delimit that edge of the stack which faces the feeding plane (4). Thus it is not necessary in advance to reserve the number of items for each layer before they are transferred into the stack; instead, the items transfer into the stack almost as one continuous flow and without need for complicated auxiliary mechanisms.

Description: An apparatus for stacking elongated i ems The present invention relates to an apparatus for stacking elongated items, especially pipes or bars of round or angular cross section, to form an angular stack, the appa¬ ratus comprising a stacking table which is provided with a raising and lowering mechanism and the support surfaces of which at least in part correspond to the shape of the stack to be produced, and an inclined feeding plane, which is substantially parallel to one side of the stack. Such stacks are formed, for example, for the purposes of bun¬ dling, storing and transport of pipes, and Fl Patents 63 554 and 67 525 and US Patent 3,262,246 can be mentioned as examples of * stacking apparatus of this type. The last-mentioned publication presents an apparatus for forming a stack of hexagonal cross section and for wrapping it. The stacking table comprises four sides corresponding to the shape of the stack being formed, and round-section items are deposited into the stack one layer at a time. However, in this known apparatus it is always necessary to reserve in the feeder that number of items needed for each layer, and only thereafter is the layer transferred to the stack. For this reason the apparatus is both relatively complicated and slow. The object of the present invention is to provide a stack¬ ing apparatus which is more efficient than the above- mentioned and other known systems, and the speed of which is sufficient even for the stacking, on a pipe production line, of large numbers of items per time unit, for example small-diameter pipes cut relatively, short. Furthermore, it is an object of the invention to provide an apparatus which is of relatively simple construction and does not require the number of items for a layer to be reserved before transfer into the stack. In order to achieve the above-mentioned objectives the invention is characterized i that the feeding plane is arranged to constitute an extension of the support surface of the stacking table at the time stacking is commenced, and always an extension of the lower side of the inclined top layer of the stack as the stacking progresses, that above the feeding plane there is fitted an upper guide, parallel to the feeding plane and at a distance from it, the guide keeping the arriving flow of items in order, in one layer, and that at the end of the feeding plane, adja¬ cent to the forming stack, there is fitted a movable edge guide, which is synchronized with the lowering movement of the stacking table and can be actuated to delimit that edge of the stack which faces the feeding plane when, owing to the shape of the stack being made, the said edge gains distance from the feeding plane as the stacking table is lowered. In the apparatus according to the invention the items are transferred into the stack almost as one continuous flow and under gravity. A new layer transfers into the stack, without separate timing, as soon as the stacking table has been lowered so much that a new layer of items will fit on top of the stack.- Owing to the edge guide synchronized with the stacking table the stack obtains the correct shape without the number of items in the layer needing to be counted. It is advantageous that the upper guide extends not only across the feeding plane but also across the upper side of the entire stack. When a hexagonal-section stack is being formed, it is advantageous to arrange the feeding plane at an angle of 30° to the horizontal plane. The invention is described below in greater detail in the form of examples and with reference to the accompanying drawings, in which Figure 1 depicts a side elevation of an apparatus according to the invention, partly diagrammatically, Figure IA depicts a diagrammatic plan view of the apparatus of Figure 1, Figures 2-7 depict the apparatus according to Figure 1 at different stages of stacking, and Figures 8-10 depict respectively different stacking stages when a stack of a square cross section is being made. Referring to Figures 1 and IA, the stacking apparatus com¬ prises a fixed frame, which is in general indicated by reference numeral 1. To the frame there is mounted a stack¬ ing table 2 , which is equipped with a raising and lowering mechanism, not shown, to raise and lower the table in the " vertical direction along guides in frame 1. The stacking table 2 comprises on the one hand an inclined support sur¬ face in the table itself and on the other hand a side sup¬ port 3, movable horizontally in the table, the side support also including an inclined support surface. The stacking table 2, the side support 3 and the fixed frame 1 together make up four sides of a hexagonal-section stack, i.e. the two lowest sides, which are each at an angle of 30° to the horizontal plane, and two vertical sides, located opposite- one another. To the frame 1 there is also coupled a feeding plane 4, at an inclination of 30°, which is thus parallel to the in¬ clined support surface of the stacking table 2. Above the feeding plane there is fitted an upper guide 6, which is parallel to the support surface and the distance of which from the feeding plane 4 is adjustable so that the distance somewhat exceeds the diameter of the items being fed to the stack. The feeding surface 4 additionally has a movable stop 7, which prevents the items, arriving along the feed¬ ing plane, from transferring to the stack before the stop is turned downwards. In the same plane with the feeding plane 4 there is additionally fitted a movable edge guide 5, which regulates the upper edge of the forming stack as the stacking progresses, as will be described below. The items to be stacked are transferred to the feeding plane by a lifting conveyor 8, which is preferably also equipped with a counter in a manner known per se. Also linked to the stacking table 2 is a strapping apparatus which, not con¬ stituting part of the invention, is not shown in the draw¬ ings. The operation of the apparatus-when stacking round-section pipes is described below, with reference to Figures 2-7. In Figure 2, a portion of the number of pipes required for a stack have been fed by the conveyor 8 to form a single layer on the feeding plane, so as to be retained by the stop 7. The support surface of the feeding plane 4 meets the inclined support surface of the stacking table 2. In Figure 3 the stop 7 has been turned downwards, whereupon the entire layer of pipes transfers downwards until the first pipe hits the inclined support surface of the side support 3. After stacking has started, the lifting conveyor 8 continues to batch pipes onto the feeding plane 4 until the number required for the stack has been fed. The stack¬ ing table 2 is lowered, whereupon the next layer is filled as soon as the distance between the first pipe layer and the upper guide 6 allows a new pipe layer to roll into place. At this stage the edge guide 5 has transferred, so as to correspond to the movement of the stacking table 2, at the blind angle of the feeding plane. When, together with the lowering of the stacking table, the stack has been filled to the extent that the vertical side adjacent to the feeding plane is complete, Figure 4, the edge guide 5 pushes synchronously with the lowering of the stacking table 2, to control the upper edge of the stack being formed. At the shift from the situation of Figure 4 to the situation of Figure 5, the stacking table 2 is low¬ ered over a distance equal to the thickness of one pipe and at the same time the edge guide 5 transfers to the left so that the number of pipes in the next layer is reduced, as shown in the figures. In Figure 6, the edge guide 5 has delimited the next-to- last pipe layer, and the last layer, for which there are only the necessary number of pipes remaining, has trans¬ ferred to its place and the hexagonal stack has been formed, and stop 7 turns upwards to prevent the access of the pipes of the next stack onto the stacking table. In Figure 7, the stack has been strapped by means of a strap¬ ping apparatus, not shown, the side support 3 has shifted outwards to release the stack for its being conveyed away. The conveying away is carried out, for example, by rollers 9, which are shown diagrammatically in Figure 1. During the strapping of the stack the lifting conveyor 8 batches onto the feeding plane 4 pipes required for the next stack. In certain cases, depending on the pipe size, the entire number of pipes required for a stack can be batched onto the feeding plane 4 before stacking is started. A similar apparatus can also be used, for example, for making a square-section stack from angular profiled items. This is depicted in Figures 8-10, and in it the side sup¬ port 3 has, perpendicular to the feeding plane 4, a support roll 10, which together with the inclined side of the stacking table 2 forms two stack-support surfaces. In other respects the operation is the same as described in connec¬ tion with Figures 2-7. However, in this case the edge guide is actuated immediately, starting from the first layer of the stack, since the free edge of the stack begins to gain distance from the feeding plane 4 as soon as the lowering of the stacking table 2 begins. It is clear that, for example, when a broad feeding plane 4 is used, items can be fed onto it from several lifting conveyors 8 and, respectively, several separate stacking tables at the end of the feeding plane can be used. The apparatus depicted in the drawings can be modified also in other respects within the idea of the invention and the following claims.

Claims: Claims 1. An apparatus for stacking elongated items, especially pipes or bars of round or angular cross section, to form an angular-section stack, the apparatus comprising a stacking table (2) provided with a raising and lowering mechanism, the support surfaces of the table at least in part corre¬ sponding to the shape of the stack to be produced, and an inclined feeding plane (4), which is substantially parallel to one side of the stack, characterized in that the feeding plane (4) is arranged to form an extension of the support surface of the stacking table (2) at the time the stacking is started, and always an extension of the inclined lower side of the topmost layer of the stack as the stacking progresses, that above the feeding plane (4) there is, parallel to the feeding plane and at a distance from it, an upper guide (6) which keeps the arriving flow of items in order in one layer, and that at the end of the feeding plane, adjacent to the forming stack, there is a movable edge guide (5) , the movement of which is synchronized with the lowering movement of the stacking table and which can be actuated to delimit that edge of the stack which faces the feeding plane (4) when, owing to the shape of the stack to be produced, the said edge gains distance from the feed¬ ing plane as the stacking table (2) is lowered. 2. An apparatus according to claim 1, characterized in that the upper guide (6) extends across the entire upper " side of the stack being formed. 3. An apparatus according to claim 1 or 2, characterized in that the edge guide (5) is in the same plane as the feeding plane (4) and is movable in the direction of the inclination of the plane. 4. An apparatus according to claim 1, characterized in that it is designed for forming hexagonal-section stacks, and the inclination of the feeding plane is 30°. 5. An apparatus according to claim 1, characterized in that the feeding plane (4) is calibrated to receive the total number of items required by a stack, in a single layer, and it has stop means (7) for retaining the number of items in place before stacking is commenced. 6. An apparatus according to claim 1, characterized in that the position of the upper guide (6) is adjustable ac¬ cording to the diameter of the items.

Inventors: HERRLIN LARS, LAHTINEN PEKKA, LUUKINEN KARI, POHTO TAPIO, THURMAN KALLE, HERRLIN, LARS, LAHTINEN, PEKKA, LUUKINEN, KARI, POHTO, TAPIO, THURMAN, KALLE
Applicants: RAUTARUUKKI OY
Application year: 1988
Main classification: B65G57
IPC codes: B65B27, B65G57