Untitled record

It is known to cover objects stacked on plates with hoods, in particular gusseted hoods and then shrink these hoods so that they hold the stacked objects together and fix the entirety of the stacked objects on the pallet.

To give an idea of ​​the size of packing units formed by this process, it should be noted that the side length of the pallets is of the order of 1 meter and that stack heights above the pallet up to 1.50 meters are not uncommon.

With this size of the packing units, two men must be used to hand-cover individual hoods over the pallet-laden pallets.

This known method is the one starting point of the invention.

It is known from US Pat. No. 3,374,599 to produce net packings in such a way that the product to be packaged is poured into cylindrical containers which are fastened on a conveyor belt and the filled containers are then transported by the conveyor belt to a net coating station . that in the Netzüberziehstation then pulled from the top of a mesh hose across the filled container away down and the filling container enclosing the hose section is separated from the tubing, that the container is then further moved into a Abbindestation with the conveyor belt and tied in the Abbindestation and finally that the filled container is tilted with the coated and tied top net tube section at a deflection of the conveyor belt to 1800, wherein the mesh tube section with the contents of the container dissolves and the freethinking, educated, at the top still open mesh hose package with the earlier pointing upwards and tied end down on another conveyor belt falls.

This known method can be considered as another starting point of the invention.

Disregarding the different size ratios, the last treated arrangement is considered as the basis of the invention.

The invention thus provides a device for covering a hose made of heat-shrinkable plastic from above via articles stacked in a plurality of layers on a base, with a device for opening and covering the flattened hose, Means for separating the hose section drawn over the articles above the articles and optionally for closing the hose section below the parting line; and a roadway for inserting the underlay with the stacked objects under the opening and top pulling devices arranged on a stand.

On this basis, it is an object of the invention to mechanize the application of film hoods on large pallets of the type discussed above in a continuous process, taking into account the fact that the stack may have irregular contours that complicate the coating.

To achieve this object, the invention proposes that are provided for opening and coating of the hose at two transversely to the roadway opposite sides of the hose of conveyor belts or chains worn gripping means, which are above the stack transversely to the road direction apart and along the stack downwards are mobile.

The arrangement of the gripping means on two transverse to the roadway sides of the tube allows loading in a loading station the pad, then einzahrei the loaded pad by means of a transport device along the roadway in the Schlauchüberziehvorrichtung without interference from the gripping devices and then covered with hose To unload the loading unit in the direction of a shrinking oven.

The gripper means pulling down the hose ensure that the hose is pulled down the full stack height even if the edges and side surfaces of the stack are irregular.

The conveyor belts can be arranged saddle-roof-shaped above the stack. This type of arrangement causes a gradual pulling apart of the hose above the stack.

The conveyor belts can be arranged in rows running parallel to the roadway direction.

The gripping devices can be designed with mechanical clamping devices; the use of mechanical clamping devices for coating film tubes on packaged goods is known per se from German Utility Model 1 881 458. Furthermore, it is conceivable to carry out the gripping devices with adhesive tapes, which are mounted on conveyor belts.

Finally, a preferred embodiment consists in carrying out the gripping devices with suction grippers; the use of suction pads for detecting packaging film material in the packaging process is known from French Additional Patent 56890.

Instead of bands can be used as a transport carrier chains, for example, when used as gripping suction tubes.

If conveyor belts are used as transport carriers, then the suction grippers can be formed in such a way that the conveyor belts are perforated and that suction boxes connected to the rear side of the conveyor belts are connected to an evacuation pump.

In order to control the suction at different points of the conveyor belts individually, you connect the suction boxes individually to the evacuation pump. Each suction box can be connected via a solenoid valve to a suction line connected to the evacuation pump.

In order to accelerate the release of a hose section already drawn over a loaded base from the suction grippers, a valve switch may be provided in the suction line via which the suction line is optionally connected to the evacuation pump or a ventilation device.

In order to be able to adapt the device according to the invention to different stack sizes, it is possible to arrange the gripping devices on frame parts which can be adjusted transversely to the roadway. For example, you can store upper frame parts for supporting the saddle-shaped upper conveyor belts at its upper end pivotally mounted on the frame and pivotally connect with the vertically arranged lower conveyor belt rows supporting lower frame parts, in which case the lower frame parts are slidably mounted in slot guides of the frame.

Critically, the transfer of each down to pulling hose section of the pulling apart of the hose section accomplishing gripping devices to the down pulling get the gripping devices.

At this critical point, one arrives at a particularly advantageous solution by arranging the saddle roof-shaped upper conveyor belt rows and the vertically arranged lower conveyor belt rows offset in the direction of the road gap and leads over a common drive shaft. Is there in this embodiment, in addition, the requirement that the upper frame members and the lower frame members are pivotally connected to each other to make an adaptation to different stack formats, so you will the pivot axis between the upper frame members and the lower frame parts in the axis of the common drive shaft lay.

If in the device according to the invention a tube not yet divided into sections is to be processed, then the separating device will be combined with a welding device which effects the welding off at the respectively upper end of each tube section. In addition, it is also conceivable to process a hose material on the machine, which is already welded off before processing transversely to the tube longitudinal direction; In this case, can be dispensed with the installation of a welding device.

If you want to process different hoses on one and the same device, so several, arranged on a horizontally displaceable carriage, can be provided with a drive means connectable Zuführrollenpaare, which are selectively adjustable in working position and connected to different supply rolls. One can also envisage this embodiment, if one wants to ensure that after consumption of a first supply roll, the next is already available for use.

The mechanization corresponding to the invention task can be further expanded by the fact that the separating device is controlled by a comparison counter measuring the length of the transported tubing. Alternatively, the separating device can also be actuated by a scanning device which responds to the passage of the hose end, as is known in a similar manner from German Utility Model 1 951 940.

If one has to count on different stack heights, then one can make the scanning element variable in its distance from the separating device.

Also, the drive of a feeder can be controlled by the Vergleichzählwerk or the scanning device.

With reference to the embodiment shown schematically in the figures of the drawing, the invention will be explained in more detail below. F i g shows. 1 is a side view according to the arrow II in Fig. 1 on the back of a conveyor belt roll and F i g. 3 an enlarged section III of a conveyor belt row according to the invention.

The fi g. 1 shows the essential parts of a device according to the invention. In the frame 1 supply rolls 2, 102 are mounted, of which a shrink tube 3 can be withdrawn via different pulleys, which is further transported in the middle of the frame by pairs of rollers 4, 104 on.

In this case, separate roller pairs are provided for each supply roller, which are arranged on a displaceable carriage 6 and can be brought into a position perpendicular above the separating and welding device 8, 9. The separation and welding devices are constructed in the usual way and should therefore not be described in detail at this point. Each pair of rollers 4, 104 has its own baffles 5, 105, which ensure that the out of the rollers hanging out down shrink tube can be exactly inserted into the separator. Below the welding device of the shrink tube 3 is guided by further guide plates 10 in the space between two rollers 12 via which conveyor belts run obliquely outwards. On the axes of the rollers 12, frame parts 11 are pivotally mounted, on which further rollers 18 and 19 for the conveyor belts and suction boxes 14 are supported.

Under the effect of the negative pressure in the suction chambers, the side parts of the initially folded shrink tube are pressed against the conveyor belts and moved down with these.

The lower hinge and guide rollers 18 of the upper conveyor belts 13 serve as drive and guide rollers for the lower conveyor belts 23, which, as best seen in FIG. 2, are offset from the upper conveyor belts 13. The conveyor belts 13 and 23 are provided with a perforation, which in F i g. 2 is indicated only schematically.

As can be seen from the figures, the suction boxes 14 are divided in the illustrated embodiment and do not extend over the entire length of the associated conveyor belt. This arrangement of split suction boxes can be achieved in a simple manner by interposing perpendicular to the strip longitudinal direction extending intermediate ribs 27. Each chamber is connected to a connecting line 15 passing through the suction box rear wall 17 with the suction line 16, wherein solenoid valves in the connecting lines, valve switches in the suction lines and the evacuation pump are not shown.

By the common roller 18 for the lower and upper conveyor belts, a seamless transition between the two conveyor belt groups is achieved, so that the shrink tube is already detected by the lower conveyor belts 23 before he must release the upper conveyor belts 13.

The axes of the rollers 18, to which both the upper frame members 11 and the lower frame members 21 are attached, are mounted in slot guides of the frame. The lower end of the frame part 21, in which the drive and deflection rollers for the conveyor belts 23 and the suction boxes are mounted for these bands is mounted on the axis of the lower guide roller 24, which in turn is mounted in slot guides 20. By adjusting, which are schematically indicated by hand wheels 22, the rollers 18 and 24 can be moved laterally outwardly with the frame members attached thereto, so that the gap between the conveyor belt rows can be adjusted to the width of the respective pallet. Since the upper frame parts 11 are not arbitrarily laterally displaceable due to their bearing on the fixed axes of the rollers 12, the slot guides are curved in a circular arc, wherein the radius of curvature lies in each case in the axis of the rollers 12.

The loaded with any goods 31 pallet 30 is retracted on a carriage 32 in the frame, which runs on sunken rails in the ground.

This makes it possible to continuously retract new cars in the stall, the already provided with the shrink tubing pallets can be retracted anchoring immediately in a tempering furnace.

By not shown in the figures scanners or a Vergleichzählwerk the separator 8 and the welding device 9 are actuated when the transported down shrink tubing has reached a length corresponding to the height of the load of the pallet. Subsequently, the now forming a hood shrink tube piece is transported by the conveyor belts further down and falls due to the switching of the valve switch from this, as soon as the lower edge of the shrink tube has reached the edge of the pallet. As already described, this switching of the valve switch can be controlled both by separate sensing means at the level of the pallet edge and by the control signals of the separation and welding device actuated counter or Abtastorgans, these signals must be delayed by a delay element so far that they only then switch the valve switch when the hood has reached the edge of the pallet with its lower edge. For the sake of clarity, the monitoring organs are not shown in the figures.

In order to prevent further shrink tubing from being transported downwards through the supply rolls after actuation of the separating device, which could hinder the cutting and welding process, the drive for the transporting pairs 4 is switched off simultaneously with the actuation of the separating and welding device. In this case, the supply roll 2 initially rotates further, which means that the watcher roller 7, which is designed as a kind of dancer roll, due to the extension of the shrink tube 3 in its loop continues to fall down. When falling below a certain height, the guard roller 7 actuates a switch which switches off the drive of the supply roll 2. The provision of such a guard role has the additional advantage that when switching on the Transportradpaare no harmful voltages can occur in Schraumpfschlauch, since in this case, first simply the guard role a piece moves upward. When the shutdown position is exceeded, the switch is actuated by the monitor rollers in the reverse direction and thus switches on the drive for the supply rollers 2 again.

Notwithstanding the described embodiment, it is also possible, for example, to use instead of the stationary suction boxes with the conveyor belts moving above suction tubes, which are guided over chains.