Patent Publication Number: US-6220000-B1

Title: Packaging device

Description:
FIELD OF THE INVENTION 
     The subject matter of the invention relates to a device for packaging, in particular on a vertical tubular bagging machine, comprising a vertically aligned fill pipe, a funnel for filling a filler into the vertically aligned fill pipe, a forming shoulder on the fill pipe for shaping a foil sheet into a foil tube, whereby the foil tube surrounds the fill pipe, an air-outlet nozzle on the funnel and a device for producing an air stream, which device is connected to the air-outlet nozzle through a supply line, in order to produce an air stream in the funnel and in the fill pipe, which air stream enables the filler to move quicker through the funnel and the fill pipe into the foil tube than would be the case without utilizing such an air stream. 
     BACKGROUND OF THE INVENTION 
     Such a device is known from the DE-OS 0 192 604. This device provides a plurality of flap-shaped air nozzles in the funnel wall or the fill pipe for the purpose of producing a downwardly directed air stream in the fill pipe in order to permit a filler to drop quicker than with the natural dropping speed. 
     A further device of this type is known from the DE-OS 33 25 300. An annular gap below the funnel is in this device used to supply an accelerating air stream. 
     The known devices have the disadvantage that they result in an uncontrolled expansion of the lower area of the foil tube to be filled and of the thus created tubular bags. 
     SUMMARY OF THE INVENTION 
     The basic purpose of the invention is to further develop a device of the above-described type in such a manner that tubular bags with a specific constant interior pressure can be manufactured in a reliable manner. 
     The purpose of the invention is attained by providing a device for packaging a filler material into bags, which device includes an air stream producing device and an air pressure measuring device. Accordingly, a measuring device for measuring the pressure existing in the lower area of the foil tube is provided, and the measuring device is connected to a measured-value indicator. 
     The invention has the advantage that the pressure existing in the lower area of the foil tube and thus in the tubular bag to be created is indicated. Thus, the strength of the air stream can be adjusted such that a specific pressure is reached. In the case that this interior pressure deviates, the air stream is changed in order to maintain a constant pressure value. 
     In the case of a different filler or a different bag size, a different interior pressure may make sense. For example, easily breakable filler parts could be packaged with a relatively high interior pressure in the tubular bag in order to protect the filler parts. 
     A measuring device, which can be easily realized and is reliable, is achieved when the measuring device includes an open ended pipe, the pipe is guided through the forming shoulder, and the measured-value indicator is provided outside of the foil tube. The pipe transmits the pressure existing in the lower area of the foil tube into a measuring device, which is, for example, provided outside of the foil tube, and the measured value of which is indicated by the measured-value indicator. Because of the measured-value indicator, the air stream can be adjusted manually or by means of a control unit. Due to the fact that the pipe is guided through the inside area of the forming shoulder, the manufacture of the tube is not influenced. 
     The measured-value transfer can occur wirelessly without any influence on the packaging device when the measuring device houses a measured-value transmitter, and a measured-value receiver is provided outside of the foil tube, which measured-value receiver is connected to the measured-value indicator. 
     A downwardly acting air-outlet nozzle in the opening between the funnel and the fill pipe has the advantage that common funnels and fill pipes can be utilized in order to move the air stream into the fill pipe. The air-outlet nozzle is provided where the funnel being slightly removed from the fill pipe creates a gap. The air-outlet nozzle provides an air stream in downward direction and creates a negative pressure in the funnel so that a filler passes more quickly through the funnel. An air stream directed downwardly by the air nozzle additionally accelerates the filler during its free fall. 
     When the air-outlet nozzle is a circular gap, which is enclosed by an annular cylindrical pressure chamber surrounding the funnel or the fill pipe, then an even air stream is created, which grabs all particles of the filler in the same manner, and which thus results in a particularly short packaging time. The pipe does not interfere with the air stream. 
     The air stream accelerating the filler is further improved when in addition to the air-outlet nozzle a suction device is provided. When the fill pipe is concentrically surrounded by a downwardly open format pipe, and the space between the fill pipe and the format pipe is connected to the suction device, then the air in the fill pipe can flow downwardly in order to shorten the falling time of the filler, and can escape upwardly through the space. The foil tube is hereby received by the format pipe and slides along same. 
     When a control unit is provided on the device for adjusting the excess pressure in a bag to be created, then the air stream can be adjusted in an advantageous manner such that a specific excess pressure is provided, for example, for a specific bag size and a specific filler. In particular in the case of a filler, for example potato chips, reacting to an air stream, such a control unit, which controls the air stream also dependent on the performance of the packaging machine, is advantageous. In addition, a bag tightly filled with air offers the filler a protection against damage. If, in addition, the control device is connected to the measured-value indicator, the control device can be dependent on the measured interior pressure to maintain the same constant pressure. 
     A technical simplification of the device exists when the device for producing an air stream is also provided as a suction device. Then a flow cycle for the air is essentially achieved. 
     The air stream is further improved by means of a further air-outlet nozzle and the falling speed can be further increased, for example, by a greater or more exact air stream. The additional air-outlet nozzle can be provided in the funnel, in the fill pipe or on the inside wall of the fill pipe. 
     When the funnel or the fill pipe is elevationally adjustable in such a manner that an air-outlet nozzle is selectively created, then packaging can be done with the device selectively with or without support through an air stream. The producible air-outlet nozzle is then created by a slight moving apart of funnel and fill pipe and is again eliminated by a moving toward one another of funnel and fill pipe. The size and thus the performance of the nozzle can be varied, when the funnel or the fill pipe are elevationally adjustable such that the air-outlet nozzle can be adjusted narrower or wider. The air stream or the falling behavior of the filler can in this manner be influenced by means of a simple elevation-adjusting device. The elevational adjustment can be taken into consideration when controlling the air stream. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention will be explained in greater detail hereinafter in connection with one figure, which shows: 
     FIG. 1 s a side view with a vertical cross section of the fill pipe, a device for packaging comprising a funnel for filling a filler into a fill pipe, an air-outlet nozzle equipped with a circular gap between the funnel and the fill pipe, which is surrounded by a pressure chamber, a device for producing an air stream, which pumps air to the air-outlet nozzle and sucks in air through a space between the fill pipe and a format pipe enveloping the fill pipe, a forming shoulder for shaping a foil sheet into a foil tube, a dosing device and a timing hopper above, two additional airoutlet nozzles in the device, and a measuring device for measuring the pressure existing in the lower area of the foil tube, which measuring device includes a pipe, which is connected to a measured-value indicator arranged outside of the foil tube. 
    
    
     DETAILED DESCRIPTION 
     A funnel  2  is used in a device  1  for packing to fill a filler measuredly delivered by a dosing device  3  and a timing hopper  4  into a fill pipe  5 . The fill pipe  5  is vertically aligned and is part of a vertical tubular bagging machine. 
     A forming shoulder  6  is used for shaping a flat foil sheet  24  into a foil tube  22 , which is received by a format pipe  7 , and into which filling is supposed to occur. 
     An air-outlet nozzle  8  exists on the funnel  2 , which air-outlet nozzle is supplied with pressurized air through a supply line  9  from a device  10  in order to produce an air stream. The air stream is downwardly directed in the fill pipe  5  in order to move the filler quicker through the funnel  2  and the fill pipe  5  into the foil tube than occurs during a free fall. 
     The air-outlet nozzle  8  is provided in an opening  11  between the funnel  2  and the fill pipe  5 . The air-outlet nozzle  8  is a circular gap  12 , to which is connected an annularly cylindrical pressure chamber  13  surrounding the funnel  2 . The fill pipe  5  is concentrically surrounded by the format pipe  7 , which is open at the bottom. A space  14  between the fill pipe  5  and the format pipe  7  is connected to the device  10  through a conduit  17 , which device serves also as a suction device  15  for the air stream exiting from below the fill pipe  5 . A specific excess pressure is achieved in the fill pipe  5  and thus in the bag to be manufactured by means of a control unit  16  on the device  10 . 
     In addition to the air-outlet nozzle  8  two further air-outlet nozzles  18  are provided, which are supplied by a separate pressure-air producer, and which are provided on the inside wall  19  of the fill pipe  5 . 
     The funnel  2  is elevationally adjustable by means of an elevation-adjusting device  20 , for example by motors, linear actuators, etc., in such a manner that the air-outlet nozzle  8  can be adjustably made narrower or wider. 
     A filler portion is initially transferred from the dosing device  3  to the timing hopper  4 . Same timely exactly drops the filler into the fill pipe  5 . The device  10  permanently supplies pressurized air to the pressure chamber  13  so that the air-outlet nozzles  8 ,  18  maintain a permanent air stream downwardly in the fill pipe  5 . However, it would also be possible to produce a pulselike air stream with the inventive device. The air stream exits at the lower end  21  of the fill pipe  5  from the fill pipe  5 . The filler moved downwardly accelerated by the air stream is there delivered into the foil tube  22  welded shut at the bottom. The air stream,on the other hand, travels through the space  14 , the cover  23  and the conduit  17  to the device  10 , which is a blower  25 . 
     In order to be able to determine and, if necessary, readjust the pressure inside of the foil tube  22  and thus inside of the tubular bag to be produced, a measuring device  26  is provided for measuring the pressure P existing in the lower area of the foil tube  22 . The measuring device  26  is connected to a measured-value indicator  27 . 
     The measuring device  26  consists of an air-pressure measuring device  28  and a hollow pipe  29  connected to the air-pressure measuring device  28 . The open end  30  of the pipe  29  projects into the lower area of the foil tube  22  and transfers the pressure existing therein to the air-pressure measuring device  28 . The pipe  29  moves through the forming shoulder  6  out of the foil tube  22 . 
     The measured-value indicator  27 , which first produces a usable measured-value signal, is connected to the control unit  16  through the line  31 . The device  10  can thus be operated dependent on the desired pressure P. 
     Although a particular preferred embodiment of the invention is disclosed in detail for illustrative purposes, it is recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.