US2009408A - Apparatus for packing pulverous material into bags - Google Patents

Description

Juy 30, 1935- K. MIDDELBOE 2,009,408

APPARATUS FOR PACKING PULVEROUS MATERIAL INTO BAGS Filed July 18, 1951 4 SheetS-Sheet l JN VEN TOR. KVQMQMMM {MM/ML July 30, 1935. n v K. MIDDELBOE Y 2,009,408

APPARATUS FOR PACKING' PULVEROUS MATERIAL `:[NTC) BAGS Filed July 18, 1931 4 Sheets-Sheet 2 Y am@ APPARATUS FOR PACKING PULVEROUS MATERIAL INTO BAGS Filed vJuly 18, 1931 4 Sheets-5h69*I 5 July 30, 1935. K, MlDDELBOE 2,009,408

APPARATUS .FOR PACKING PULVEROUS MATERIAL INTO BAGS Filed July 18, 1951 4 Sheets-Sheet 4 Patented July 30, 1935 UNITED STATES APPARATUS FOR PACKING PULVEROUS MATERIAL INTO BAGS Kristian Middelboe, Frederiksberg, near Copenhagen, Denmark, assigner to F. L. Smidth & Co., New York,v N. Y., a corporation of New Jersey Application July 18, 1931, Serial No. 551,697 In Great Britain July 24, 1930 6 Claims.

The lling oi bags, particularly valve bags, with pulverous material, such as cement or the like, and with simultaneous weighing of the material, is subject somewhat to the diniculty that 5 the bag cannot be lled completely with material, because the latter, when iilled into the bag,

is mixed with some air. This is especially true in the operation of lling machines in which the cement or other material, by addition of a 10, certain quantity ofair, is given such a fluid consistency that the material will flow like a liquid under the influence of gravity as a constant stream through the pipes through which the material is filled into the bag. In other types of filling machines, such as those in which the material is forced through the nlling pipes by means of a rotary vane or a fast worm conveyor, some air will be suspended in the material supplied to the bag.

It has been attempted to overcome this diiliculty in some degree by giving the valve opening of the bag such a .shape that the escape of air from the bag is facilitated, and also by rapping the outside of the bag during the filling process, whereby also lthe removal of air entrapped in the material will be facilitated. In spite of all such precautions, however, the degree of filling has never been quite satisfactory.

The present invention has for its object, in lling material in an air-mixed state, to increase the degree of lling beyond what has been attained heretofore. According to the invention this object is attained by stopping, for one or more periods, during the lling of a bag, the

, supply of material to the bag in order thus to give the entrapped air a chance to escape from the material. The material is not supplied continuously to the bag, but periodically, which of course causes a corresponding increase in the 40 filling time, but as shown by experiments the degree of iilling of the bag is increased so much that the saving in bag material will be far in eX- cess of the costs due to the increase in filling time.

This delay, however, may be shortened somewhat by using the above mentioned known means for facilitating the removal of air from the material nlled into the bags. A good ventilation at the valve opening of the bag will shorten the period during which the supply has to be interrupted in order to let the air escape from the material in the bag. This increased ventilation may be attained partly by a powerful exhaust of air at the valve opening, and partly by the provision of ample openings for the air to escape at the top end of the bag. The iilling time may also be shortened by rapping on the outside of the bag, during the supply of material as Well as during the periodical stops.

In the drawings, in which a convenient and practical embodiment of the invention is illustrated,

Figure 1 is a View in elevation of a non-rotary filling machine iitted with devices for the periodic cutting oli of the supply of material to the 10 bag.

Figures 2 and 3 are detail views on a larger scale of some parts of the mechanism shown in Figure 1, Figure 2 being a View in sectional elevation as seen from the right hand in Figure 3, and Figure 3 being a View in elevation, as seen from the left hand in Figure 2.

Figure 4 is a view similar to Figure 1, showing a device constructed in accordance with the present invention and providing for the inter- 20 ruption of the iilling operation twice, thus illustrating a mechanism wherein the filling operation may be interrupted a plurality of times.

Figure 5 is a view similar to Figure l, showing .a rotary type filling machine.

The filling machine proper consists mainly of a filling tank l, which is carried by supports 2, and from the bottom of which the material is supplied as a uniform stream, by way of a stationary discharge pipe 3 and a movable filling pipe 3" joined thereto, to the bag suspended on the last mentioned pipe. The connection between the two pieces of pipe is such as to permit relative movement and may be of telescopic construction.VV

By means of a skew joint 3 the lilling pipe 3 is divided into an upper and a lower part supported each by one of two arms 5 and 8, respectively, carried by the hanger 6 of the Weighing mechanism. The arm 8 is pivoted about a point l of the hanger 6 of the weighing mechanism, and during the lling of the bag the said arm is maintained in the position shown on the drawings by means of a latch lever 8, which is pivoted at a point I 0 on the hanger 6, a stop 9 of the latch 9 engaging an arm 8 extending from the arm 8. The free end of the lever 9 is fitted with a guide roll 9".

The top end of the hanger 6 is suspended from one end of a two-armed lever l l, the other end of which on the other side of the tank I carries another hanger l2 which supports Weights I3 adapted to counterbalance the bag until such time as it has received the predetermined weight of material. The hangers 6 and I2 are guided by brackets le and i5, respectively, on the side of the tank l. These brackets serve also to limit the motion of the hangers, when the filled bag is removed from the machine, the brackets being provided. with stops Iii and llfacing downward and upward, respectively, and the hangers 6 and l2 being iitted with corresponding stops it and il" respectively. Y

The discharge pipe 3 for the tank I constitutes a gate for the material and this gate is governed from the outside by means of a lever mechanism in such a manner that the gate is held invopen position when the lever mechanism is locked in a raised position, but is closed when the saidv mechanism is released, which is effected autoniatically by the hanger G moving downward in consequence of the tilting of the balance beam l i. The mechanism serving to effect this release is shown in detail in Figures 2 and 3 from which it will'be seen that the discharge pipe 3 is a flexible tube and may be compressed between a movable roller 4B and a fixed bracket 4i. 'Ihe roller iscarried by the vertical arm of a bell crank lever i8', 43, i3, pivoted on'a stud 44 on the tank i, the horizontal varm I3 supporting ar guide roll 28, which is actuated by devices to be described. The locking and releasing mechanism for this lever may consist of apawl device such as that to` bek described and adapted to maintain the lever in position, as long as the hanger 6 is in its upper position, but released indirect consequence of the downwardmotion of the hanger.

Y A device of this sort, as shown in Figures 2 and 3 may comprise a spring-controlled pawl 46 mounted in the hollow arm 45 of the bell-crank lever I3', 53, I8" and engaging a groove 48 in a cylinder la suspended on the bracket M. When the notch 5! of `a latch 52 xed on the hub 43 of the Vbell Vcrank lever engages a trigger 50 extendingwfrom the cylinder 49, the pawl d is compelled to remain in the groove 48 and thereby keep the bell-cranklever in a raised position, so that the tube 3 is not choked, but when a lug 53 on the hanger y, in the'downward movement. of this latter, presses the latch: 52 downward, so as to f' release the trigger 5D, thepawl 4,6 is also released,

and the weight i? on the arm i8 may cause the bell cranktocompress and close the tube 3'. A stop 511 is fixed to the hollow arm 45 of the bellcrank lever to tilt the latch 52 .together with the bell-crank lever, so that the trigger 5D by gravity may assume the position in which it is to be locked when the bell-crank lever kis raised again. .Y i i The hanger 6 is tted with a stud 2 1, on which rests a lever 22 carrying a weight ,2l and a guide roll 23, which is actuated by a device to be de. scribed. The lever is shown as pivoted at 24 on a bracket 25, secured to the tank l. Ihe mass of the weight 2i should be adjusted so as torcorrespond to the weight of the bag li-when filled with cement mixed with air, for example, less than the intended full weight of the bag, at ,which weight it is desired to stop temporarily the further supply of material to the bag in order that air may escape therefrom. t

The levers 9, iiil and 22, armed with the guide rolls 9, 2o and 23, are governed by a vconstantly rotating governing device shown at the lefthand side ofV Figure 1. This device consists of a vertical shaft 26 rotated inthe direction indicated b y the arrow 2g, from a shaft 28 by means of gear wheels 2l' and 21".' This shaft 26 supports, at three different levels, corresponding to the position'of the levers 9, I8 "and 22, three cam discs attached to the shaft, viz., a cam disc 30 corresponding to the lever 9, another cam disc 3| corresponding to the lever I8', and a third cam disc 32 corresponding to the lever 22. The rst disc 3Q is tted with a cam Sil directed upward, the second disc 3 lV with two or Vmore spaced cams 3i and 3i directed upward, and the third disc 32 with a cam 32 of considerable length.

The operation of the described mechanism is as follows, it being assumed that in the position of the mechanism shown an empty bag has just been hung on to the filling tube 3:

At this moment the cam 35 on the disc 3| is just passing the guide roll 2i? and will therefore rock the lever i8', 133, i8, ermitting the discharge pipe 3 to be opened, the lever being .maintained in this position by the locking devices described. At the same time the drop of the cam 3,2 of the disc 32 passing below the guide roll 23 and permits the adjusted weight 2i to exert its determined pressure on the hanger 6. This extra load on the hanger causes the weighing mechanism to come into equilibrium at the moment when the bag a is still lacking a certain part of the prescribed full weightrof rnaterial,v and when this occurs Vthe1lever i3', Q3, IB" will beV released and the filling tube 3' will be closed by the roller dii, so that the flow of material will be interrupted. After the lapse of a period of time, during which no material is added to the bag, the high part of the cam 32" will pass below the guide roll 23 and lthe hanger 5 will be relieved of the lever weight 2l.

During the period when no material is addedv `roll 20 and will, therefore, once more. rock the lever I3', d3, i8", whereby the discharge pipe 3 will be opened again for furtherV filling of Vthe bag. The pipel 3 will again be closed'by the further downward movement of the hanger S when the bag has been fully filled to the prescribed degree. When this has been accomplished the filled bag will be removed automaticallyY by the action of the cam 3o o-n the disc 3d on the guide roll 9, whereby the Vlatch lever il is lifted, releasing the stop 8V and the arm and permittingV the filling pipe 3 to swing downward on the pivot 'i and discharge the bag. v

In the foregoing description it is assumed that the stream of material filling the 'bag is interrupted once during the lling vof a bag, but there is nothing to prevent the mechansm4 from being arranged in such a manner, by suitable arrangement of the cams on the discs that the flow of material can be interrupted'more than once during the filling of the bag. For example, Figure 4; illustrates a filling mechanism wherein provisionis made for the Yinterruption of the filling operation twice.V The reference characters have been applied to Vthis igure to correspond with the reference characters which have been applied to Figure l and it will be seen that the` disc 32 is formed with an additional cam 32'. to

engage the roller 23 and raise the weight 2i' toY takelits pressure from the hanger 6; Pressure is exertedby the weight when the roller- 23 is dis# engaged by the cam 32" at the time the cam 3i on the disc 3l isengaging the guide roll 2Q hanger causes the weighing mechanism to come into equilibrium at a time when the bag 4 still lacks a certain part of the prescribed full weight of material. At such time the lever I 8', 43, I8 will be released and the filling tube 3 will be closed by the roller 40 to interrupt the filling operation. After the lapse of a predetermined time during which no material is `introduced into the bag, the high part of cam 32 will pass below the guide roll 23 and the hanger 6 will be relieved of the lever weight 2I.

During the-period when no material is added to the bag the air therein has an opportunity to escape. When the period of interruption is ended, the other cam 3| on the disc 3I will be situated below the guide roll 20 and will therefore once more rock the lever I8', 43 and I8 whereby the discharge pipe 3 will be opened again for the further filling of the bag. After the lapse of a brief period of time the roll 23 is disengaged by the cam 32 and the pressure then exerted on the hanger 5 by the weight 2i, together with the weight of the material in the bag will overbalance the weights I3, when the bag 4 is stiil lacking a certain part of the prescribed weight of the material, so that the lever I8', 43, I8l will be released and the iilling tube 3 will be closed by the roller 4G. After the lapse of a further period of time, during which no material is added to the bag the high part of the cam 32 will pass below the guide roll 23 and the hanger 6 will again be relieved of the lever weight 2|.

During the period when no material is added to the bag, the air in the bag has an opportunity to escape from the material introduced into the bag and when this period is ended the other cam 3I on the disc 3I will be situated below the guide roll 20. The lever I8', 43, I8 will thus once more be actuated, opening the discharge pipe 3 for a final filling operation. The pipe 3 will again be closed by the further downward movement of the hanger 6 when the bag is fully iilled to the prescribed degree.

It will be understood that in the operation of such a mechanism as that just described in which provision is made for the interruption of the iilling operation twice, the initial filling of the bag takes place when the roller 23 rests upon the disc 32, the roller 40 being then held from the filling tube 3. This initial filling will be continued until the weight of the material in the bag plus the weight 2| is suiiicient to pull down the hanger 6 against the counterbalance weights I3. At this time the bag has not been completely filled and during the interruption of the filling the air may escape. To continue the filling of the bag after the escape of the air the cam 32 raises the roller 23 and thereby takes from the hanger 6 the effect of the weight 2I. As the roller 23 is thus lifted the cam 3I" of the disc 3I acts upon the roller 20 and, through the lever I8', 43 and I8, removes the roller 40 from the nlling tube 3 and so permits the filling to be continued. This iirst supplemental filling then continues so long as the roller 23 is held in its elevated position by the high part 32', but when the cam 32 passes from below the roller 23 then the hanger 6 is subject to the action of the weight of material then in the bag 4 plus the weight 2I and these combined weights will depress the hanger 6 and so cause the roller 40 to stop the iiow of material through the tube 3'. It being assumed that in the operation of this mechanism the bag is not yet completely iilled and that an opportunity should be aiiorded for the further escape of -air from the bag, a further supplemental flow of material should be permitted. To accomplish this the cam 32" then engages the roller 23 and lifts the weight 2I fromthe hanger 6. At this time the cam 3I of the disc 3i engages the roller 20 and throughthe lever I 8', 43 and I8 moves the roller 40 from the iilling tube 3 and permits the iiow of material to be resumed. This second supplemental iiow willthen continue until the weight of the accumulated material in the bag 1l counterbalances the weights I3 and so again effects the interruption of the iilling after which the now completely filled bag is discharged from the machine.

Figure 5 illustrates a iilling and weighing machine of the rotating type constructed in accordance with the present invention. This machine corresponds generally in function and during operation to the machine shown and described in Figure 4. The discs 30, 3I and 32 on the stationary type of machine have been replaced by rings bearing the same reference character and upon which the correspondingly identined cams are formed. The rings are stationary while the machine rotates causing the rolls 9, 23 and 23 to move along the rings to be actuated by the respective cams. In so far as the construction in Figure 5 is concerned, it will be seen that the relatively stationary and rotating parts have been reversed, illustrating the manner in which the present invention can be applied to the weighing and filiing mechanisms of the rotating type, as well as to mechanisms of the non-rotary type.

I claim as my invention:

l. Apparatus for filling bags with pulverous material comprising a source of supply, a iilling pipe, a counterbalanced hanger by which the bag is supported during the filling, means to prevent the flow of material through the iilling pipe, means whereby the operation of said iiow preventing means is initiated by the downward movement of the hanger as the weight of the bag increases, independent means acting, while the bag is supported by the hanger, upon the iirst named means to permit the flow of material to be continued, and a cam and operating connections whereby said independent means is actuated.

2. Apparatus for iilling bags with pulverous material comprising a source of supply, a iilling pipe, a counterbalanced hanger by which the bag is supported during the filling, means to prevent the flow of material through the filling pipe, means whereby the operation of said iiow preventing means is initiated by the downward movement of the hanger as the weight of the bag increases, means to apply downward pressure to the hanger to cause downward movement thereof when the bag is partly lilled, and means independent of the hanger to relieve the hanger of the pressure of the last named means and permit the filling of the bag to be continued.

3. Apparatus for iilling bags with pulverous material comprising a source of supply, a filling pipe, a counterbalanced hanger by which the bag is supported during the iilling, means to prevent the flow of material through the filling pipe, means whereby the operation of the iiow-preventing means is initiated by the downward movement of the hanger as the weight of the bag increases, a weighted lever bearing normally on the hanger to cause downward movement thereof when the bag is partly iilled, and a rotating camdisc to cooperate with said lever and relieve the hanger of its Weight.

4. Apparatus for lling bags with pulverous material comprising a source of supply, a filling pipe, a counterbalanced hanger by which the bag is supported during the lling, meanscomprising a Weighted lever to prevent the flow of material through the filling pipe, and a cam and operating connections independent of the hanger and arranged to cooperate with said means to permit the flow of material through the lling pipe.

5. Apparatus for lling bags with pulverous material comprising a source of supply, a lling pipe, a counterbalanced hanger by which the bag is supported during the iilling, means toapply downward pressure to the hanger to cause downward movement thereof when the bag is partly Vfilled, means to prevent the flow of material c through the lling pipe, means to effect the discharge of the bag when filled, and cam discs rotating together and cooperating with said severalemeans respectively.

6. A machine for iilling bags with pulverous a device to control the ovv of material through n the lling pipe, mechanism to control said device and tending normally to move the device to closed position, Weighing mechanism, a vertically movable suspending rod connected to the weighing mechanism and supporting the bagpto be iilled, means to retain said controlling mechanism in open position, means actuated by the movement of the suspending rod to release the controlling mechanism and permit it to stop the flow, and means to reset the controlling mechanism to open position, such means including an arm of the controlling mechanism and a cam arranged tocofact with said arm to reset the mechanism to open position at a predetermined point in the operation of the machine. e

KRISTIAN MIDDELBOE.

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