US2922443A - Method and apparatus for de-aerating bags during filling - Google Patents

Description

Jan. 26, 1960 L. M. JONES ETAL 2,922,443

METHOD AND APPARATUS FOR DE-AERATING BAGS DURING FILLING Filed Nov. 5, 1956 INVENTORS LESTER M. JONES BY FHA A/K RAYMOND Ll/VDA J r 2 ATTORNEYS United States Patent METHOD AND APPARATUS FOR DE-AERATING BAGS DURING FILLING Lester M. Jones, Daly City, and Frank Raymond Linda, Mill Valley, Cahf.

Application November 5, 1956, Serial No. 620,227 6 Claims. (Cl. 141-7) This invention relates to a method and apparatus for de-aerating or removing excess air from bags as they 7 are being filled with granular or powdery substance.

In our co-pending application entitled Container Venting Apparatus and Method, Serial No. 596,683,

filed July 9, 1956, now abandoned, we described the filling and concurrent venting or de-aerating of a bag 'through the valve of a conventional paper valve bag.

' through various parts of the bag maybe omitted preventing loss of materials and resulting in cleaner exteriors of the bags when they are handled andstored.

Furthermore, the bags may be filled more quickly, more accurately as-to weight and more nearly full so that bags of somewhat smaller size may be used for a given quantity of a particular commodity.

One difiiculty that has been encountered in the use of a vacuum nozzle for de-aerating bags as they are being filled results from the withdrawal of an excessive amount of the powdered commodity just prior to complete filling of the bag. Since the filling spout and vacuum nozzle are disposed in the upper portion of the bag, the final part of the filling operation results in a turbulent condition in that portion and much of the commodity is withdrawn by the vacuum nozzle. While this material is subsequently reclaimed, the condition nevertheless results in inefiiciency and slightly slower filling.

It is the object of the present invention to provide a method and apparatus for de-aerating bags in which the amount of the commodity withdrawn during filling is greatly minimized.

More specifically it is an object of the invention to provide a method and apparatus in which the suction or vacuum employed for de-aerating is discontinued just prior to complete filling of the bag so that none of the commodity is withdrawn when the most turbulent condition prevails in the vicinity of the vacuum nozzle.

Further and more specific objects and advantages of the invention and the manner in which it is carried into practice are made apparent in the following specification wherein reference is made to the accompanying drawing.

In the drawing:

' Fig. l is a schematic view illustrating a bag filling spout with a suction nozzle combined therewith and illustrating diagrammatically the electric circuit by means of which the suction through the spout is discontinued at a predetermined time; and

Fig. 2 is a sectional view taken on the line II-lI of the combined filling spout and suction nozzle.

2,922,443 Patented Jan. 26, 1960 Conventional apparatus for filling bags includes a scale having a beam which supports a filling spout, the open valve of a bag to be filled is placed over the spout so that the weight of the bag is imposed on the scale. The commodity with which the bag is to be filled is introduced under pressure, and usually with a considerable quantity of extraneous air, through the spout until a pre -determined weight is attained to lower the beam of the scale and automatically interrupt the flow of material through the spout by closing a valve. According to the present invention, the suction which de-aerates the bag during filling is interrupted just prior to the complete filling of the bag when the powdered commodity is most turbulent and most likely to flow out through the vacuum nozzle.

Referring to Fig. 1 of the drawing, a filling spout is illustrated at 10 as supported on a vertical bar 11 which the spout by any suitable means one form of which is here illustrated as an impellor 28 rotated by a motor,

not shown. The impellor rotates in a clockwise direction, as viewed in the drawing, and receives material from a hopper 29. Combined with the filling spout 10 is a vacuum nozzle provided by welding or otherwise securing a segment of a'tubular member 14 to its upper surface. 'The welding or securing means is terminated short of the outer end of the member 14 leaving'a narrow opening in the area indicated at 15 for the admission of air when suction is applied to the nozzle portion 14. Suction from any'convenient low pressure source is communicated thereto through a conduit 16 which enters a fitting 17 on the spout, the interior of which communicates with the member 14.

A solenoid valve 18 of conventional construction is disposed in the suction conduit 1-6 and is energized by a circuit indicated at 19 which includes a timer 20 controlled by a micro-switch 21. The micro-switch is adapted to be closed by upward movement of a lever 22. It should be closed at the time that filling of the bag starts. In this case the lever 22 is engaged by a cam 23 projecting from a small plate secured as by screws 24 extending through a slot 25 to a frame portion 11 of the scale which supports the nozzle 10. The slot 25 permits adjustment of the cam 23 vertically of the frame member 11.

In the position of the parts illustrated in Fig. 1, the bag is being filled and the solenoid valve is open so that extraneous air is being withdrawn from the upper portion of the bag at approximately the same rate that it enters through the nozzle 10. Assuming that filling of the bag with a particular commodity, such for example as cement, requires about six to seven seconds, the timing switch will be set to close a circuit to the solenoid valve about one or one and one-half seconds before the bag is filled, thus closing the solenoid valve shortly before the bag is completely filled and preventing withdrawal of large quantities of the cement or other powdered material during the final portion of filling when turbulence in the upper end of the bag is high. When the bag is filled its weight lowers the beam of the scale, and the frame member 11 attached thereto by the cam 23 has no effect on the micro-switch as it depresses the arm 22 during this lowering movement. In practice the beam of the scale is latched in its lowered position by conventional mechanism not shown, and when an operatrated as provided by ing through a venturitypeejection device In s uch a construction the solenoid valve disclosed in' the present in advance of I I I I I thus providing the same effect of discontinuing thesuctor places an unfilled bag over the spout lt't he also trips the latch which permits raising of the beam and actuates the micro-switch again toset the timer in operation for I that period of time slightly shorter than is required for filling the bag. I It is to be understood that the timer is of the type which resets itself fora new cycle aft'ereach cycle ofits operation. I I I I I I In the co-pending application referred to above, the suction for de-aerating the container being filled isillusv the medium of compressed air passapplication may be applied to theipressure line at a point its connection with the venturi deviceand suction through said tube prior in time to, and du-ring the completion of the filling operation 7 2. In combination witha conta ner filling apparatus in which a container is supported by a scale to weigh the contents for determining when it ts full, suction with a filling spout for filling con- 4. In combination with a container filling apparatus of the kind in which the container is supported on a scale and weight of material in the container moves a scale part downwardly to discontinue filling when the container is full and in which the scale part is moved upwardly to initiate filling of another container, a filling means, a suction conduit associated with the filling means "to deaerate the container being filled, valve means to discontinue suction, a timer forv controlling the operation of said valve means to discontinue suction prior to complete filling of the container, and means actuated by upward movement of said scale part, to initiate operation of 'the timer.

5. The method of filling I which is being filled bymaterial thatis accompanied by extraneous air which comprises first introducing said material and withdrawing air by suction from the containermsimultaneously, then discontinuing I the suction gprior-to the) time that the filling of the container is completed, and then-completing the filling o f thecontainer. ,6. The method of filling and .de-aerating a container which is beingfilled by material that is accompanied by extraneous air which comprises first introducing saidmaterialand Withdrawing air by suctionappl ied within ,the upper portionof the container simultaneously, and

e then, when thecontainer is nearly full and a tunb ul e nt means for withdrawing excess'air tromthe container as;

' it is being filled, timing means to discontinue suction'at 'a predetermined timeperiod and while thecontainer is still being filled, and means actuated by movement of the scale for setting said timingmeans in operation,

I I 3. In combination witha-container filling apparatus l in which a container :is supported by a scale to weigh the contents for determining when' it is full, suction means .for withdrawing excess air' f rom the container as it is being filled, an electrically actuated. valve for interrupting saidsuction, timing means in the circuit, to thevalve, and means to initiateoperation of the timing means when filling of the container-commences.

7 condition prevails in its upper portion, discontinuing said isuction andcontinuing the introduction of material until the'container is full.

References Cited in the file of this patent I UNITED STATES PATE NTS I I 4 1,037,824 Fasting se ta, 1912 q1',491',071' 'iShelor Apr. 22; 1924 2,738,119 'Haygarth Mar.f13; 1956 FOREIGN PATENTS I 629,1 78 Germany 1936 and de-aerating a container

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