US 3443609 A
Description (OCR text may contain errors)
May 13, 1969 P. H. A. WEHREN APPARATUS FOR FILLING VALVE BAGS WITH PULVEIROUS MATERIAL Filed Sept. 21, 1966 M m u 4/ o h I INVENTOR. /2/- 1Q Wei/e27 United States Patent 3,443,609 APPARATUS FOR FILLING VALVE BAGS WITH PULVEROUS MATERIAL Peter H. A. Wehren, Krefeld, Germany, assignor to Erwin Behn Verpackungsbedarf G.m.b.H., Krefeld, Germany Filed Sept. 21, 1966, Ser. No. 581,055 Claims priority, application Germany, Sept. 28, 1965, B 83,916 Int. Cl. B65b 1/04 US. Cl. 14168 4 Claims ABSTRACT OF THE DISCLOSURE A device for filling bags with pulverous or granular material having a feeding line for filling connection with a bag, in which the feeding line is subdivided into a larger cross-sectional branch and a smaller cross-sectional branch each of which has associated therewith control means for individually controlling said branches, the arrangement being such that both branches are effective during the major portion of the filling operation while the smaller cross-sectional branch only is eifective during the last phase of the filling operation.
The present invention relates to an apparatus for filling valve bags with pulverous material according to which the flow of material in the feeding line to the filling connection is shut off by a valve. With a heretofore known device of this type, below the spot Where a main container leads into an auxiliary container, there is provided a nozzle for compressed air, the air jet of which passes by the mouth of the main container and is directed toward the mouth of the auxiliary container. By means of such a device it is not possible Within a short filling time to obtain a precise filling weight of the bag because the said nozzle feeds the pulverous material either in the form of a coarse current or in the form of a fine current. When the feeding takes place in the form of a coarse current, an unsatisfactory precision as to weight is obtained, whereas when the feeding takes place in the form of a fine current the filling operation takes a considerable time.
There has also become known a valve bag packing machine which is provided with a porous wall inclined at approximately 45 degrees with regard to the horizontal, while two air feeding lines end below said wall. The compressed air of one of said lines impacts upon the central section of the wall, whereas the compressed air of the second line impacts upon the lower section of the wall. This known embodiment yields a satisfactory filling within a short time, but also fails to solve the problem of obtaining a precise filling weight within a short time because the post sliding of the filling material on the inclined surface is rather difficult to control so that there exists the danger of an undesired post filling.
According to another heretofore known filling device there is likewise employed a porous wall inclined at approximately 45 degrees with regard to a horizontal while a feeding line leads to the bottom side of said wall. This arrangement additionally has a valve acting in the manner of a hose clamp and adapted to block the flow of mate- 3,443,609 Patented May 13, 1969 rial, said valve being located behind said wall when looking in the direction of flow of the material. Such shutoff valves have the advantage of being able to operate almost without delay which means that they close immediately after a corresponding impulse has been emitted, and thus will assure a high precision in the filling of the bags. Thus, with such an arrangement it has been possible to employ large flow cross sections of the filling material in order to reduce the filling time. These known fast closing valves, however, have the drawback that a closing of the valve even by a fraction of a second ahead of or after the intended closing time brings about that the admissible tolerance range of the weight is exceeded to a considerable extent.
It is, therefore, an object of the present invention to provide an apparatus for filling valve bags with pulverous material which will overcome the above-mentioned drawbacks.
It is another object of this invention to provide an apparatus for filling valve bags with pulverous material which will be able on one hand to maintain a short filling time and on the other hand will assure a high precision of the filling weight of the bag.
Still another object of this invention consists in the provision of an apparatus as set forth in the preceding paragraph, which will make it possible, by simple means and in a short period of time to change the ratio-precision of filling weight to filling speed-in favor of the precision or in favor of the speed.
These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:
FIGURE 1 illustrates partially in section the entire filling apparatus without the Weighing mechanism and without the container to be filled.
FIGURE 2 shows on a somewhat larger scale than FIGURE 1, the two hose clamping valves.
FIGURE 3 represents a further embodiment of the invention with uniform cross sectional line for the fine current.
The present invention, which relates to an apparatus for filling valve bags with pulverous material in which the flow of material in a flexible hose is blocked by a valve acting in the manner of a hose clamp, is characterized primarily in that an exchangeable pipe section having a smaller diameter than the hose extends coaxially into the flexible and compressible hose. The pipe section extends preferably over 73 of the length of the hose of the valve and is held in the valve housing by means of wings or plates arranged at one end of said pipe section and directed radially outwardly. The fine current passing through the pipe section is adapted to be blocked by a second valve which is likewise designed in the manner of a hose clamping valve and may be coaxial with regard to the flexible hose of the first valve. For flow technical reasons, the pipe section may be provided with a flexible hose extension which, similar to the pipe section can be exchanged for the latter by a hose extension of a larger or smaller diameter, said flexible hose extension being centrally held in the second hose clamping valve. Such an arrangement affords the possibility of a uniform flow section of the fine current while the quantity of this fine current is determined by the selection of a suitable pipe section and the blocking of the current of the fine material.
Referring now to the drawing in detail, the corresponding wall of the container 1 holding the material to be charged has connected thereto a flange 2 of a valve 3 to which the ends 4a, 4b of a flexible hose 4 are connected. The inner chamber 5 of the hose merges with the bore 6 of fiange 2 and is closed in an airtight manner with regard to the remaining inner chamber 7 of the valve housing so that when introducing a pressure medium, preferably compressed air, through the connection 8 into the inner chamber 7, the hose 4 will be compressed or pinched together instantaneously so as to assume the position shown in FIG. -2 in dot-dash lines and designated with the reference numeral 4.
'Flange 9 of valve 3 has a bore 10 which corresponds to the bore 6 of flange 2. Flange 9 has a cylindrical extension 11, the inner chamber of which merges with the bore 10.
A pipe section 12 extends coaxially into the interior of hose 4 and has a length which amounts to approximately of the length of hose 4. This pipe section is formed of non-yieldable material so that when hose 4 is instantaneously pinched together in view of the pressure medium introduced into chamber 7, hose 4 will in its position 4' rest on pipe section 12 without causing a change in the cross section of said pipe section '12.
Pipe section 12 is held in its position by wings or webs 13 arranged at the front end 12a which extends into bore 10 and extension 11, said wings or webs extend-ing radially outwardly and being so shaped and arranged that the pipe section 12 can easily be slipped into bore 10 and extension 11 and can with the same ease be withdrawn therefrom. Suitable locking means (no-t illustrated) will prevent pipe section 12 from undue displacement with regard to its illustrated position.
Connected to extension 11 or flange 9 is one end of a hose 14. This connection may be effected by a shell 15 or any other suitable connecting element. The second end of hose 14 is by means of a second shell 16 connected to the annular extension 17 of a stationary member 18 which preferably is a part of a scale. Hose 14 can be compressed or pinched into the position 14' in a manner similar to hose 4. To this and two rollers 19 of two piston rods 20 are provided. The pressure medium acting upon the pistons of said piston rods is supplied through nipples 21.
OPERATION OF THE DEVICE OF FIGURES 1 AND '2 The operation of the devices of FIGURES 1 and 2 is as follows:
-It may be assumed that hoses 4 and 14 are in the position shown in solid lines in FIGURE 2. The material to be filled into the container passes from the material holding container 1 through the total cross section of hose 4, Le. also through pipe section 12 in the form of coarse current to the filling mouth F (FIG. 1). The filling mouth F is in a well-known manner connected to the weighing device which emanates the control impulses for the device. After the bag has been filled by a coarse current shortly before reaching its rated content, compressed air is supplied to the inner chamber 7 whereby hose 4 will instantaneously be pinched against the pipe section 12 so that the material to be charged can pass from the container 1 only through pipe section 12 to the filling mouth F. This step of transforming a coarse current to a fine current can be eflected very suddenly so that the coarse current can be permitted to flow without encountering a lack of precision in the weight of the bag. In other words, the fine current need in contrast to heretofore known devices flow only for a short time while a high precision in weight of the filling of the bag can be maintained.
The closing off of the fine current is effected by a pinching movement of rollers 19 and the inherent pinching of hose 14 into the position 14'. In view of the mechanical adjust-ability of the valve device acting in the manner of a hose clamp, which valve device consists of hose 14 and the members 19 to 21, it is also possible to gradually reduce the fine current.
With regard to the embodiment of FIGURE *3, pipe section 12 is at 12]; extended beyond the Wings or webs 13. In bore 30 of member 18 there is provided a short pipe section 31 which has wings or Webs 32 arranged in a star-shaped manner which are shaped and arranged similarly to the wings or webs 13 on pipe section 12. At 33 pipe section 31 extends beyond the webs or wings 32 in the direction toward the valve 3. The ends of a flexible hose 34 are slipped upon the extension of pipe section 12 at 1211 and onto the extension of pipe section 31 at 33. The inner diameter of hose 34 corresponds approximately to the inner diameter of pipe section '12. Thus, a conduit or passage of nearly uniform cross section is obtained from the start of pipe section 12 to the end 32a of pipe section 31.
By exchanging pipe section 12, if desired at the time the hose 34 is exchanged for a pipe section with smaller or larger diameter, it is possible to control the magnitude of the fine current. The control possibility is extremely precise because the fixed cross section of pipe section '12 will assure a precise quantity of material per time unit. Aside from the fact that the flow conditions change only seldom, the quantities of flow of coarse current and fine current are at the same ratio as the free coarse section of hose 4 and the respectively selected pipe section 12.
It is, of course, to be understood, that the present invention is by no means limited to the particular constructions shown in the drawings but also comprises any modifications within the scope of the appended claims.
What I claim is:
1. A device for filling bags with pulverous and granular material, which includes: conduit means having inlet means for connection with a supply of material to be filled into a bag and also having outlet means for discharging said material into a bag, said conduit means comprising a first passage of a larger cross-section and a second passage of a smaller cross-section, each of said two passages cornmunicating with said inlet means and said outlet means, and control means respectively associated with said two passages for respectively and individually controlling the same to thereby selectively feed material to be filled into a bag simultaneously through both passages over a selected major portion of a bag filling operation and subsequently only through said smaller crosssectional passage during the very last phase of the filling operation.
2. A device for filling bags with pulverous and granular material, which includes: conduit means having inlet means for connection with a supply of material to be filled into a bag and also having outlet means for discharging said material into a bag, said conduit means comprising a first flexible hose having one end in communication with said inlet means and also having a second flexible hose with one end in communication with the other end of said first hose while having its other end in communication with said outlet means, a substantially rigid pipe arranged substantially coaxially with and in radially spaced relationship to said first flexible hose so as to define an annular passage therewith, said pipe having one end in communication with said inlet means and having its other end in communication with the interior of said second flexible hose and through the latter with said outlet means, first control means associated with said first flexible hose and operable to squeeze the latter against said rigid pipe to thereby block the flow of material through said annular passage, and second control means associated with said second flexible hose and operable to squeeze said second flexible hose so as to pre- 5 6 vent the flow of material from said inlet means through References Cited said second flexible hose to said outlet means.
3. A device according to claim 2, in which said first v UNITED STATES PATENTS and second flexible hoses in unsqueezed position have ap- 2,770,439 11/1956 Stafford et X proximately the same inner diameter. 5 2,898,088 '8/1959 Alder 138-45 X 4. A device according to claim 2, in which the length v of said pipe from its area of communication with said HOUSTON Primary Examinersecond flexible hose in the direction toward said inlet Us Cl XR means equals approximately two-thirds of the length of said first flexible hose. 10 13845; 141--392; 2'5l5