The invention relates to a procedure and device for the accelerated filling of sacks, wherein the sack to be filled is situated on a moveable feeding hopper, which moves the sack in the conveying direction during the filling process, wherein a device for folding the sealing tabs of the sack, provided with holders for the open sack, is simultaneously moved in the transport direction of the sack, and takes the sack together with a sack holder at the meeting point. The feeding hopper and sealing tab folder along with the sack holder are then moved apart in the respectively opposite direction, the sealing tabs of the sack are folded and the sack is sealed.[0001]
Sack filling devices according to prior art usually encompass a metering device with stationary feeding hopper. Carousels with rotating feeding hoppers are also known. The filling devices according to prior art share in common that the sack sealing tab folders are each arranged on the filler neck of the feeding hopper. As a result of this design, the sack remains under the feeding hopper after filled until the sealing tabs of the sack have been folded and the sack with folded sealing tabs is transferred to a device for sealing, bonding or the like. If necessary, the time for which the sack is kept under the feeding hopper is decreased if the sack is already sealed at that location.[0002]
The filling devices according to prior art share in common that the sack capacity rate per hour is limited by the fact that the sealing tabs cannot be folded under the filler neck of the feeding hopper for the next filling cycle. Another limitation of filling capacity stems from the fact that the sack to be filled remains stationary during the filling process, and only moves after the filling process is completed. In particular in high-performance filling machines, this results in considerable losses of time owing to the time it takes to transport the sack out of the area of the filler neck and release the filler neck for the next sack to be filled.[0003]
The output of high-performance filling machines is currently limited to about 1,300 sacks per hour by the aforementioned disadvantages in prior art.[0004]
The object of this invention is to provide a high-performance filling machine for sacks and a procedure for the accelerated filling of sacks in which the sacks can be filled at a higher filling capacity per hour. Another object is to provide a procedure and device that ensure filling reliability with respect to the respective quantity to be filled and filling operation without malfunctions.[0005]
The objects are achieved according to the technical features of the independent claims. Preferred embodiments are described in the subclaims. Additional advantages to the present invention will be illustrated in the description below.[0006]
The present invention proceeds from a known sack-filling device comprising a filler material-metering device, a feeding hopper with filler neck and devices for folding and sealing the sealing tab of the sack to be filled.[0007]
All known and conventional metering devices for filler materials can be used as the filler material-metering device within the scope of the present invention. Metering can be volumetric or gravimetric, depending on the required application and the filler material. However, the invention is not limited to this.[0008]
Sealing sack within the scope of the present invention refers to any form of tightly sealing the sack, e.g., bonding, welding, sewing, etc.[0009]
This invention is based on the trick of decoupling the devices for folding the sealing tabs from the filler necks of the feeding hopper, and also making the feeding hopper and separate sealing tab folder moveable in the transport direction of the sack. This trick distinctly increases the sack filling capacity in comparison to prior art, since the time for which the sack stays under the feeding hopper is reduced. In addition, the time necessary for moving the sack outside the area under the filler neck is decreased. Filling capacities of 1,500 sacks per hours can be easily realized with the device according to the invention.[0010]
In its most general embodiment, the device has a feeding hopper arranged under the metering device, wherein the feeding hopper can be moved in the direction of the transport path of the fillable or filled sack. The feeding hopper is designed in such a way that it can be loaded by the metering device over the entire range of its motion. The sealing tab folding device is independent of the feeding hopper, and also movable in the transport direction of the fillable or filled sack, wherein the sealing tab folder and feeding hopper are moved synchronously.[0011]
In its initial setting, the feeding hopper is provided with the sack to be filled, and held by clamps arranged at the lower end of the filler neck of the feeding hopper. After the empty sack has been locked in place, filling begins via the metered dispensing of filler material from the metering device, which releases the filler material in the feeding hopper. The feeding hopper with the sack on it is moved in the transport direction of the sack during the filling process already. At the same time, a separate sack holder moves toward the feeding hopper in the transport axis of the sack. If the positions of the separate sack holder and feeder hopper provided with the now-filled sack are in a location that enables the transfer of the sack from the feeding hopper to the sack holder, the movements are stopped, and the filled sack is transferred. The filler necks and separate sack holder then change their direction of movement, moving away from each other. Therefore, the feeding hopper and separate sack holder execute an oscillating or reciprocating motion over time.[0012]
The respective traversed path preferably measures about half the width of a sack, which combines to an entire width of a sack based on the additional traversed paths of the feeding hopper and separate sack holder. If necessary, the traversed path can be lengthened by the percentage necessary to make room for the respective holders and folders to engage.[0013]
After running through one cycle, i.e., after reaching the initial position of the feeding hopper, sufficient space is created below the filler neck to attach the next sack.[0014]
Provided the sack holder and feeding hopper have reached the respective initial position, the filler neck of the feeding hopper is provided with a new sack to be filled. At the same time, a sealing tab folder engages, taking over the filled, open sack from the separate sack holder, and folding the open sealing tabs of the sack. The sealing tab folder can be designed as a knife folder.[0015]
The sealing tab folder moves coordinated with and at a constant distance from the feeding hopper. The sealing tab folder can be arranged on the conveyor, e.g., a drivable sled that carries the feeding hopper. The distance between the sealing tab folder and feeding hopper neck can measure roughly one sack width, if necessary expanded by the space required for the clamps of the filler neck and sealing tab folder to engage.[0016]
The sealing tab folder can also be provided with a sealing device to seal the filled sack after its sealing tabs have been folded. The sealing device can be designed as a welding device, for example.[0017]
In the next basic cycle, i.e., with the next reciprocating motion of the feeding hopper, the sealing tab folder is also moved in the transport direction of the sack, and hence the filled and sealed sack located therein. In another embodiment, the sealing tabs can already be folded during the forward motion in the transport direction. Likewise, the folded flap can be sealed in a separate sealing device.[0018]
After the oscillating motion has reached the final position, i.e., relative to the initial position, the sack holder relays the filled sack to another transporting device, e.g., a conveying belt.[0019]