FI118685B - Device for lifting and moving veneer sheets - Google Patents

Description

118685

APPARATUS FOR LIFTING AND MOVING SHEETS

The invention relates to an apparatus for lifting and moving veneer sheets, as disclosed in the preamble of claim 1.

Wood veneers are used as a basic component in plywood manufacturing and also for coating various surfaces such as furniture and doors. The wood veneers are cut from warm, steamed-wood logs by cutting, turning or planing, and then the veneer sheets thus produced are dried by various drying methods. The veneers can be dried, for example, on a line in which the veneers are arranged to pass through several levels through a line on which the hot air is circulated. 15 Transferring veneer sheets requires some device to lift a single veneer sheet from the stack and transfer it, for example, to a drying line or plywood production line. It is known for this purpose to use a suction lift which can be moved above the line and the veneer stack. The suction-20 lifter is provided with suction, which causes the veneer sheet to adhere to the underside of the lifter, allowing the veneer sheet to be lifted and moved.

••• issa In known vacuum box-type vacuum cleaners, the bottom of the • •: suction unit is substantially completely mesh and forms:. ·, Ί completely the surface on which the veneer sheet is sucked under vacuum. However, these devices have had problems with:; * ♦ security. A large number of veneer sheets fall during the transfer ···; ***. more than one veneer ··· 30 sheets at a time may be stuck in the unit and lift. In addition, the lift must be individually adjusted; manually for veneer sheets of different lengths, which causes problems * · · and slows down the handling of veneer sheets if, for example, • · *** is lifted from a stack of veneer sheets of different lengths or where the plywood • · V.! is stacked unevenly. If the veneer sheet is too long for the elevator dimension, the end of the veneer sheet will hang j · * and the veneer sheet may fall off the elevator easily. Similarly, * · ·. If the veneer sheet is short in relation to the hoist, temporary • suction cups must be placed in front of the earthed bottom of the net to prevent bypassing the suction. Also, prior art elevators of 11868585 do not work properly if the surface of the veneer stack is uneven, for example, raised in the middle, or if the veneer sheets are hunched. Because of these problems, the vacuum lifter must be monitored during operation and if, for example, veneer sheets fall or become attached to the vacuum lifter more than one at a time, the situation must be corrected. Fallen veneer sheets can be damaged, and in addition, repairing defects causes extra work and danger and slows down production.

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Prior art solutions are also disclosed in the patent publications NL9300248 and US3338615. The solution according to the NL publication is mainly intended for suction lifting of corrugated sheets. It has 15 downward-facing supports that allow an air gap between the bottom and the retractable corrugated sheet. Similarly, in the US publication, whose solution is primarily intended to lift cartons by suction, Fig. 6 shows bottom-down supports which also allow an air gap between the bottom and the cartonboard to be lifted. The problem with the solution of both publications is that even if the air gap in the bottom and. even though it is formed between the lifting plate, it is open at all its sides, which prevents a significant air lifting • · · * air channel.

It is an object of the present invention to eliminate the above drawbacks and to provide a cost-effective and simple operation; ***; and robust equipment for lifting and moving veneer sheets. The apparatus according to the invention has j *. 30 is characterized in what is stated in the characterizing part of claim 1. Other embodiments of the invention are characterized by what is stated in the other claims.

An advantage of the solution according to the invention is that the invention: ·. 35, the suction grip and carrying capacity are significant. significantly better than previous solutions. It follows • · · * * that the suction lift can be equipped with a smaller machine 3 118685 to save weight, space and cost. It also has the advantage that no veneer sheets are dripped from the elevator and no more than one veneer sheet is held at a time. It is also an advantage that the veneer sheets can also be lifted from unevenly stacked stacks, as well as stacks with veneer sheets of different sizes without having to be individually adjusted for the sheets of different sizes. In this case, the length of the veneer sheets is not a limiting factor. A further advantage is that the vacuum lifter according to the invention can be used to lift veneer sheets from stacks 10 having a non-flat upper surface, for example the center of the stacks being elevated, or stacks having individual sheets of humps. A further advantage is that the solution according to the invention is simple and inexpensive to implement. Due to the above-mentioned advantages, the vacuum cleaner of the invention helps to improve the safety and capacity of veneer handling.

The invention will now be described in more detail by way of one embodiment, with reference to the accompanying drawings in which: Figure 1 is a schematic and simplified view of the apparatus of the invention in the direction of · 2 · · · ··· / B in Fig. 2, and partially cut away, · Fig. 2 is a schematic and simplified view of: ·: Fig. 1 is a sectional view taken along line A-A of Fig. 1, Fig. 3 illustrates a simplified and bottom view of the immunization device of the invention, Fig. 4 shows a schematic and a simplified view of Fig. 4. Figure 5 is a schematic and simplified view of the suction box of Figure 4, viewed from the end.

. **! 35 • ··, ·. Figures 1 and 2 show the immunizer 1 · «according to the invention in its operating environment. The main components of the suction lift 1 are

A

118685 delta-adjustable body 1a, suction boxes 2, suction ducts 3 and 6, and suction or vacuum blower 9, vertical beams 13 serving as support structure for suction lift 1 and substantially horizontal top beams 14 attached to their top ends. along the guide rails 21, the suction lift 1 is arranged to move with the wheels 22 of the body 1a substantially horizontally and reciprocally by means of a transfer mechanism 23.

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The body Ib of the sucker 1 includes at least a frame-like and substantially rectangular upper body structure 16 having wheels 22 movable on guide rails 21 at each end thereof. Figure 1 is shown in direction B of Figure 2 and cut so that part of the front upper beam 14 has been removed; the upper frame structure 16 is cut in the direction of travel of the suction lift 1, for example in the middle of the frame structure. Attached to the frame structure 16, for example near the corners of the frame structure, are fastening rods 5 which are substantially vertical to the upper bay 20, for example there are, for example, four pieces, one fastening rod 5 near each corner. syydessä. The lower ends of the fixing rods 5 are free. A substantially vertical force cylinder 15 is attached to the inner surface of each of the fastening rods 5 from its 15 cylinder members. The body Ib 25 further includes a lower frame frame, which is • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · lower and substantially rectangular in shape.

The structure 4 suspended from the upper frame structure 16 by means of force cylinders 15, whose lower ends of the force cylinders 15, i.e. the piston rods, are attached to the lower frame structure 4 at their lower ends.

··· • · · · * 1 'Two elongated suction boxes 2 are fastened to the lower frame structure 4 of the body Ib by means of fastening means 4a substantially at the same height and parallel to each other. 35 and the horizontal distance. At the upper surface of the suction boxes 2 • · *] ·, j, suction channels • * · 3 are attached at their first end, the other ends of which are connected to a main suction duct 6 5118685 belonging to the suction lift 1; and 6 through the suction boxes 2. At least the main suction channel 6 is flexible so as to allow movement of the suction boxes 5 with respect to the fan 9. In this embodiment, two suction channels 3 are secured to each suction box 2, which are secured between the central portion and the ends of the suction box 2. By means of vacuum, the veneer sheet 10 engages the suction lift 1 with the lower surface of the suction box 2 over the veneer sheet 10. The lower frame structure 4 of the body Ib and the suction boxes 2 accompanying it are moved vertically by force cylinders 15 in connection with the processing of veneer sheets 10.

The suction boxes 2 are box-shaped, elongated enclosures partially open to 15 women at the bottom. At the lower edge of each suction box 2, tubular rubber seals 8 extending at least downwardly from the bottom of the suction box 2 are secured to both long sides of the suction box 2 and a spacer 20 the spacer bracket 7 is adapted to prevent the air channel 20 between the veneer sheet 10 and the bottom of the suction lath. The rubber pins · »ί · ί · threads 8 and the spacer bracket 7 are substantially the length of the suction box 2 * .ϊ .: 25. The structure and function of the suction box 2 are explained in more detail in the description of the figures below.

* * · · • * * * ♦ ·

Figure 2 is a schematic and simplified view ···

The apparatus according to the invention is a sectional line A-A of Figure 1

30 cut along. The height of the suction boxes 2 is the suction box. ···, at its midpoint, and the height drops to both ends of the suction boxes • · * 1 *.

• • • • • • • * * · ♦

Fig. 3 is a simplified and bottom view of the suction boxes 2 of the suction lift 1 of the suction lift 1 according to the invention. The suction boxes 2 · are connected to one another by means of a lower frame structure · ·· 4 and fixing means 4a. Figure 3 also shows the rubber seals 8 attached to the side edges of the suction boxes 11 and the spacer brackets 7 attached to the center of the suction boxes longitudinally in the center of the suction boxes 2 with suction openings 17 provided with filter nets to prevent larger debris from the boxes 2 are provided with substantially closed bottom plates 19, which, however, are provided with additional suction openings 18 with filter nets at the ends of the suction boxes 2. The purpose of the Li suction openings 18 is to provide the additional suction 10 required, for example, in certain problem situations. Such problems include, for example, unevenly stacked violin stacks and veneer stacks that are centrally raised. The veneer sheet 10 to be lifted by the suction lift 1 may have a minimum length of the suction opening 17 in the middle of the suction box and substantially the length of the suction boxes 2 at its maximum.

Figures 4 and 5 show schematically the side and end views of the suction boxes 2 according to the invention. The bottom plate 19 differs from the prior art solutions 20 in that it closes the bottom of the suction box 2 except for the central inlet 17 and the smaller auxiliary suction openings 18 at the ends. In the prior art solutions, the bottom plate is mesh and thus open throughout the suction box. a trip. The arrows in Figure 4 show the air flow generated by suction in the air channel 20 formed between the bottom of the suction box 19 and the retractable: veneer sheet 10 and itself in the ··· ·: · * · suction box 2.

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. ···. formed by the bracket 7 and the rubber seals 8, and the retractable veneer sheet 9 · · 10, open at their ends and substantially closed at the periphery. The air flow velocity »·· * ... increases in the direction of the air duct, increasing suction power, 9 9 * * ·· * whereby the veneer sheet 10 is very firmly adhered to the rubber seals 8. Because of the high suction power, the spacer bracket 7 is needed in the middle of the bottom of the suction box so that the suction does not pull the veneer sheet / 35 kia 10 from the middle to the bottom of the suction box 2, as the hub size decreases, power will decrease.

• · »• ·· • * 7 118685

For example, the veneer sheets 10 are treated by the method of the invention: for lifting the veneer sheet 10, the suction box 2 is lowered onto the veneer sheet 10, thereby forming an open elongate air duct 20 over and below the veneer sheet 10 which is sealed from below and between the veneer sheet 10, at least during the attachment step of the veneer sheet 10, by means of a substantially suction enhancing air flow by means of a vacuum generating fan 9 and suction channels 3 10 and 6. Preferably, this suction booster air flow is produced in addition to the anchoring step throughout the lift, transfer and landing. To enhance the suction effect, the airflow generated between the suction box 2 and the veneer sheet 10 15 is made to pass at least part of its path in the air duct substantially parallel to the bottom surface of the suction box 2 at the bottom of the suction box 2. Further, at least a portion of said air flow is directed to pass between the suction box 2 and the veneer sheet 10 towards the suction opening 17 in the middle of the bottom of the suction box 2.

From the foregoing, it is seen that the elongate air duct 25 20 at the bottom and at each end of the suction boxes 2, which is closed at the bottom by a veneer sheet 10, is essential for the solution of the invention. at the same time, the fan 9 causes a suction to effect a • # j # * peak air movement in the air duct 20.

1 «· • ♦ • · ···

It will be clear to one skilled in the art that the invention is not limited to the above embodiments, but may vary within the scope of the following claims. Thus, for example, the structure of the suction lift may be • · · V. * different from the above. For example, instead of two suction hubs, only one suction can be used in the suction box. 35 hubs by placing it in the center of the suction box, whereupon suction: occurs at the center of the suction boxes.

• «* • * 8 118685

It will also be apparent to one skilled in the art that other structures may be used instead of rubber seals to provide the required air passage between the bottom of the suction box and the retractable veneer sheet. The bottom of the suction box may, for example, have a flexible or suitably flexible structure and may have openings with filter nets in substantially the same manner as previously mentioned. Thereby, the partially closed bottom would be raised upward by the suction effect, and would be formed between the bottom and the veneer sheet to be lifted, for example a duct air channel resembling a circular segment, in which air could flow in the longitudinal direction of the air channel

15

It will be further understood by one skilled in the art that closed air ducts at their ends or at least at one end may also be used instead of air ducts at the lower surface of the suction box.

20 • # 4 «4 * 4 * 4 • · • 4 · • * · ♦ 4 • · · • · 4

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* · • · 4 4 * 4 • · 4 4 4 4 4 4 «44 444 444 4 4 4 4 44 4 • 4 • 4 4 44 • 4 4 4 4 4 4 4 44 * 4 * 4 4 4 4 4 4 4 * 4 * 4 *:: 44 * * * • 4 4 44 • 4 4 4 4 4 4 4 «* *

Claims (5)

118685 Apparatus for lifting and moving veneer sheets (10), comprising an suction lift (1) with at least one suction box 5 (2) and a vacuum fan (9), the suction box (2) being at least partially provided with a closed bottom plate (19) (19) downwardly extending brackets arranged in conjunction with the bottom plate (19) to form an air gap to accelerate the air flow, characterized in that the downwardly extending supports from the bottom plate (19) extend at least downwardly from the bottom of the suction box; elongated seals (8) disposed in combination with the base plate (19) and the veneer sheet 15 (10), which are sucked in to the suction box (2), to provide an air flow accelerating, substantially closed but open at each end. Apparatus according to claim 1, characterized in that the elongated seals (8) are tubular rubber seals. • ··· J *** Apparatus according to claim 1 or 2, characterized in that at least the center plate of the bottom plate (19) of the suction box (2) • »* * · !. The 25 sections have an inlet port (17). • · • * · • · · ** · «ί, ϊ, ϊ Device according to any one of the preceding claims, characterized in that, in addition to the suction opening (17) in the middle of the bottom of the suction box (2), the suction box bottom plate (19) has a plurality of additional suction openings (18). * ·· e e • · t · * Device according to any one of the preceding claims, characterized in that the central part of the bottom ···: ... 5 of the bottom of the suction box (2) has a spacer bracket extending from the bottom to the bottom (*). 7). • · • · · • * * e · ίο 118685