US3301281A

US3301281A - Bag ejector device

Info

Publication number: US3301281A
Application number: US320154A
Authority: US
Inventors: Erwin M Lau
Original assignee: Black Products Co
Current assignee: Amcor Flexibles North America Inc
Priority date: 1963-10-30
Filing date: 1963-10-30
Publication date: 1967-01-31
Anticipated expiration: 1984-01-31

Description

im. 31, 1967 E. M. L Au 3,301,281

BAG EJECTOR DEVICE Filed oct. 5o, 196s s Sheets-sheet 1 FIELE Jan. 3i, 1967 E. M. LAU 3,301,281

BAG EJECTOR DEVICE Filed Oct. 50, 1963 I5 Sheets-Sheet 2 Jan. 3l, 1967 E. M. LAU

BAG EJECTOR DEVICE 3 Sheets-Sheet 3 Filed Oct. 30, 1963 nited States Fatent fitice 3,301,281 Ftented Jan. 31, 1967 3,301,281 BAG EJECTR DEVICE Erwin M. Lau, Dolton, lll., assignor to Black Products Co., Chicago, Ill., a corporation of liiiinois Filed Oct. 30, 1963, Ser. No. 320,154 8 Claims. (Cl. 141-272) The present invention relates to a bag ejecting device for the spout assembly of an automatic bag filling machine.

In the bag filling machines with which the present invention is concerned, the bag is a valve type of bag, and the weight of the bag is supported entirely from the spout or spout assembly. Examples of scaling mechanisms for this type of machine are shown in my prior Patents 2,936,994, granted May 17, 1960, and 3,062,307, granted November 6, 1962, and in my copending application Serial No. 171,200, filed February 5, 1962, now Patent No. 3,133,608.

The sensitivity of the scaling mechanism is greatly increased by use of a fioating frame type of construction, as shown in the first patent, or by a parallel axis type of construction, shown in the latter patent, for the reason that the weight of the bag is transmitted to the scale mechanism through a single element, namely, the spout assembly.

It is an object of the invention to provide an improved spout assembly which includes a platform or saddle disposed beneath the spout, together with means to rock the saddle forwardly at the conclusion of the bag filling operation so that the valve of the bag will slide off the spout and drop forwardly on to a hand truck, moving belt, or the like.

According to this arrangement, at least a portion of the bag weight is taken up by the saddle, but this does not affect the mechanics of the system since the saddle is a part of the spout assembly.

The saddle actuating means is characterized by the fact that it is mounted on the spout assembly and is a self contained unit, in the sense that it does not react against any part of the frame of the bag filling machine. As a result, there is no connection between the spout assembly and the machine frame which would take up a portion of the bag Weight and thus diminish either the accuracy or the sensitivity of the scaling mechanism.

The present invention is illustrated with respect to a suspended spout assembly of the cradle type shown in my aforesaid copending application Serial No. 171,200, although it may be applied to the floating frame type of construction in much the same manner as the settling device shown in my copending application Serial No. 83,224, filed January 17, 1962, now Patent No. 3,115,905.

According to my invention, the saddle is mounted on a pair of links which define a certain type of forward and upward movement, and the actuating mechanism is preferably in the form of a self contained air cylinder of which the piston is pivotally mounted on the spout assembly so as to provide a self aligning characteristic.

Another feature of the present invention is that the motion of the saddle has a decided vertical component so that the spout will be relieved of the bag weight during the ejecting operation. Preferably, the saddle .also has a rear bag backing portion so that the horizontal component will be effectively transmitted to the bag.

Another object of my invention is to provide in a bag ejecting device, an improved saddle construction in which the saddle is formed in two parts which are spaced from each other to provide a slot to accommodate the lower portion of a bag when in its elongated empty condition, in combination with means for supporting each part independently of the other and for moving them in unison with each other.

Other objects, `features and advantages will become apparent as the description proceeds.

With reference now to the drawings in which like reference numerals designate like parts:

FIG. l is an elevation of a portion of a bag filling machine embodying my invention;

FIG. 2 is a front elevation of FIG. 1; l

FIG. 3 is a horizontal section taken along line 3-3 of FIG. 7;

FIG. 4 is a horizontal section taken along line 4-4 of FIG. 7; l

FIG. 5 is a vertical section taken along line 5 5 of FIG. 3;

FIG. 6 is a horizontal section taken along line 6 6 of FIG. 7; and

FIGS. 7, 8 and 9 are enlarged side elevations similar to FIG. 1, and showing changed positions of the parts.

FIGS. 1 and 2 show a bag filling machine 10 which comprises a frame 11 and a material supply chamber 12 supported by the frame 11. The bag filling machine also comprises a spout 13 which communicates with the supply chamber 12 through a flexible tube 14. A pinch valve 15 is provided to cut off the flow of material from the chamber 12 through the spout 13. The bottom wall of the chamber 12 comprises a diffuser pad (not shown) which causes fluidization of material in the lower part of the chamber so that it will flow through the spout 13 and into a bag 19 which is suspended from the spout 13. The details of the fiuidizing and feeding operation are pointed out in my aforesaid prior Patent 2,936,994.

The operation of the pinch valve 15 is controlled by scale mechanism 16, as is described more fully in the aforesaid patents. The scale mechanism inclu-des a parallel axis beam 17, that is, a beam wherein the fulcrum axis is parallel to the axis of the spout 13. The beam 17 is supported on fulcrum posts 18.

The scale mechanism 16 also includes a spout assembly 20 which is in the form of a cradle or U-shaped member freely suspended from the front and rear arms of the beam 17. The spout assembly includes a front plate 22 having an opening therein, the spout being mounted in the opening.

Depending from the lower end of the front plate 22 are a pair of spaced hanger rails 23. An ejector device 24 is mounted on the hanger rails 23.

The ejector device comprises a base 25 and saddle v means in the -form of a pair of saddle plates 26. The

lbase 25, as shown in FIGS. 3 and 4 comprises a front bracket 27, a rear bracket 28 and a ibridge 29. An air cylinder 30 lis mounted on the bridge 29.

The front bracket 27 has a pair of forwardly extending spaced arms 31 which support a linkage shown in FIGS. 7 to 9. The linkage includes a front link 32, a rear link 33, and a top link 34. The saddle rplates 26 are secured to the top lin-ks 34 fby suitable screws 35. The rear link 33 is lon-ger than the front link 32 so as to impart and upwardly and lforwardly movement to the saddle, as shown in FIGS. 7 to 9.

The air cylinder is preferably of the rubber diaphragm type shown in FIG. 4 which permits a certain wobbling movement of the piston 36 so that the piston can accommodate itself to positions other than the exact axial position. A suitable diaphragm type air cylinder is manulfactured by Bendix Westinghouse and identified as Tylpe 9 Rotochamber, Catalog No. 228,230.

The piston 36 carries at its outer end a yoke 37 which is connected to the two rear links 33. Thus, the use of the diaphragm type air cylinder 30 provides a sel-f aligning characteristic even thou-gh the cylinder is bolted to the -bridge 29 as shown in FIG. 3. In the alternative, a standard air cylinder with a sliding piston may be used, provided that the air cylinder is pivotally mounted on the base 25 according to usual cylinder mounting practice.

The rear bracket 23 is provided with an opening 3S to accommodate the yoke 37. lThe hanger rails 23 are located between the arms of the yoke 37 and the side ilanges of the rear bracket 28 and serve as .guides for the yoke. The hanger rails 23 are provided with indentations 40 which interlock with a pin 41, as shown in FIGS. 3 and 8 so that the elevation of the ejector device 24 may be regulated in accordance with the length of the bag.

A lfeature of the present invention is that the saddle means is formed in two halves 26 which are spaced from each other to provide a slot `42 therebetween. The slot 42 accommodates the seam and lower end portion of an empty bag. An empty bag is somewhat longer than the bag when filled, but the length contracts as the material yfills' out the bag. According to my invention, each saddle plate 26 is supported independently of the other. The saddle .plate .forms a part of the linkage, but by providing a separate top link 34 which overlies the arms $1 of the front bracket 27, it is possible to provide an arrangement in which each saddle plate 26 is structurally independent of the other, thus eliminating cross bracing, and which does not require that the lin-k pins 43 Ibeextended across the slot 42.

In other words, as shown in FIG. 7, when in its normal position, the weight of the bag is transmitted from the saddle means 26 to the base 25 along the abutting surfaces 44 (see FIG. 7) of the

elements

31, 34. Thus, no stress is placed on the

links

32, 33, or the link pins 43, except during the bag ejecting operation. i

During the initial stages of the bag filling operation, the weight of the bag 19 and contents is entirely taken up -by the spout 13, but as the bag fills out` and shortens, a part o'f the weight will be taken up by the saddle plates 26. At the time that the scale mechanismftrips, it is probable that most of the bag weight is taken up by the saddle plates 26. However, this does not change the lever arm of the scale mechanism, nor does it introduce any such `binding action as would reduce the sensitivity due to the fact that both the spout and the ejector device 24 are a part of a spout assembly 2t? which is freely suspended :from the parallel axis beam 27, and hangs 4freely in a vertical plane. The center of 4gravity of the spout assembly is located at a point between the front and rear arms of the beam 17 so that no horizontal reaction need be v.provi-ded at the lower end of the hanger rails 23. The actuating means for the ejector, being in the form of a self contained air cylinder Sti, does not react against any portion of the machine frame 11 with the result that no structural connection is required which would take up a portion of the bag weight to reduce accuracy of the scale.

Although the operation of the lejector device results in a shifting of the mass of the assembly comprising the spout assembly 20 and the 'bag and contents, nevertheless, due to the cradle construction, the equilibrium is not disturbed. Although the spout assembly, including the cross bar 45 is of considerable mass, increased stability can be provided by adding counterweights 46 to the rear portion of the cross bar 4S.

In operation, after the bag 29 is placed on the spout 13 with the seam and lower fportion of the bag extending downwardly into slot 42, the ba-g Vfilling operation is in-itiated by suitable means, such as a start button. When the predetermined amount of material has been fed into bag, the tripping of the scale mechanism 16 automatically cuts of the feeding operation, by virtue of a microswitch 47 which actuates the pinch valve 15. The microswitch 47 may also actuate a solenoid valve, not shown, which supplies air to the air cylinder 3) so that after a delay of a fraction of a second, inherent in the control mecha-y nism, the piston 36 will be extended, thus rocking the rear links 33 forwardly and upwardly. The cranks of the iourabar linkage being of unequal length, the saddle plates 26 will follow a path substantially as shown in FIGS.

7 to 9, in which the vertical component of saddle motion is predominant initially, thus relieving the spout 13 of any portion of the bag weight. As a result, the bag slides easily olf the spout as the horizontal component becomes .more predominant. The saddle plates 26 have vertically disposed 'backing portions 48 which transmit the horizontal component to the lower portion of the bag with the result that there will be no tendency for the bag to buckle at its midpoint and bind at the spout, which sometimes would occur when the ratio of bag contents to capacity is less than standard.

Although only a preferred embodiment of my inven-f tion is shown and described herei-n, it will be understood that vario-us modifications and changes may :be made irr the construction shown without `departing yfrom the scope of my invention, as pointed out by the appended claims.

I claim:

1. A bag iilling machine comprising a spout assembly including a spout, a hanger rail depending from said spout assembly, and a bag ejector mounted on said hanger rail and being entirely supported from said spout assembly,l said bag ejector comprising a base, saddle means disposed above said base, link means connecting said saddle means and said base, said link means including a front link and a rear link, said rear link being longer than said front link, power means mounted on said base and including an actuating member, and means connecting said actuating member to one of said links to tilt said saddle means upwardly and forwardly to eject a bag resting thereon.

2. A bag ejector for a bag lling machine having a spout assembly and hanger rails depending from said spout assembly, comprising a base, means for mounting said base on said hanger rails, a pair of laterally spaced saddle plates disposed above said base, link means connecting each one of said saddle plates and said base, each of said link means including a front link and a rear link, said rear link being longer than said front link, power means mounted on said base and including an actuating member, and yoke means connecting said actuating member to said rear links to tilt both of said saddle plates upwardly and forwardly to eject a bag resting thereon.

3. A bag ejector as claimed in claim 2 in which said saddle plates are disposed forwardly of said hanger rails, and in which said power means are disposed rearwardly of said hanger rails to partially offset the weight of said saddle plates and link means.

4. A bag ejector as claimed in claim 2 in which said base includes a rear bracket including rearwardly extending side anges, said hanger rails being disposed adjacent to said side ilanges, and a removable pin extending through said side flanges and bearing on the rear edge of said hanger rails and interlocking therewith to provide an adjustable mounting for said base.

5. A bag ejector as claimed in claim 4 in which said hanger rails are provided with indentations on the rear edges thereof for cooperation with said removable pin.

6. A bag ejector as claimed in claim 2 in which said power means is an air cylinder of the rubber diaphragm type, said actuating member being the piston of said air cylinder, whereby said piston is self aligning with respect to the connection between said yoke means and said rear links.

7. In a bag filling machine having a balance beam, the combination of a spout assembly including a horizontal spout, said spout assembly being suspended from said beam, a bag ejector device including a saddle suspended from said spout assembly and being spaced beneath said spout by a distance such that at least a portion of the weight of said bag will be taken up by said saddle, and means imparting a -combined translational and rotational movement to said saddle for moving said saddle as a whole upwardly so as to relieve said spout from the weight of said bag, and simultaneously to tilt the bag forwardly so that said bag will slide olf of said horizontal spout.

8. In an automatic bag filling machine having a spout assembly and a hanger rail depending from said spout assembly, a bag ejector comprising a bracket having two forwardly extending arms, means for mounting said bracket on said hanger rail, a saddle plate disposed above each arm, linkage means connecting each saddle with each arrn, each of said linkage means including a top link normally disposed parallel with each arm and in Vertical alignment therewith, a front link, and a rear link, said front and rear links connecting said top link with sai-:l arm whereby in collapsed position each top link rests on a bracket arm, each top link being secured to a saddle plate so that the weight on each saddle plate is taken up by one of said arms, said rear link being longer than said front link, and means for tilting both of said saddle plates upwardly and forwardly to eject a bag resting thereon.

References Cited by the Examiner UNITED STATES PATENTS 5 1924 Jacquelin 74-26 8/1931 Peterson et al. 177-118 X 6/ 1944 Peterson 141-272 X 2/ 1956 Buttereld et al.

1/1964 Rose et al. 141-68 X 5/1964 Lau 177-118 FOREIGN PATENTS 8/ 1959 Australia.

5/ 1962 France.

LAVERNE D. GEIGER, Primary Examiner.

E. I. EARLS, Assistant Examinez'.

Claims

7. IN A BAG FILLING MACHINE HAVING A BALANCE BEAM, THE COMBINATION OF A SPOUT ASSEMBLY INCLUDING A HORIZONTAL SPOUT, SAID SPOUT ASSEMBLY BEING SUSPENDED FROM SAID BEAM, A BAG EJECTOR DEVICE INCLUDING A SADDLE SUSPENDED FROM SAID SPOUT ASSEMBLY AND BEING SPACED BENEATH SAID SPOUT BY A DISTANCE SUCH THAT AT LEAST A PORTION OF THE WEIGHT OF SAID BAG WILL BE TAKEN UP BY SAID SADDLE, AND MEANS IMPARTING A COMBINED TRANSLATIONAL AND ROTATIONAL MOVEMENT TO SAID SADDLE FOR MOVING SAID SADDLE AS A WHOLE UPWARDLY SO AS TO RELIEVE SAID SPOUT FROM THE WEIGHT OF SAID BAG, AND SIMULTANEOUSLY TO TILT THE BAG FORWARDLY SO THAT SAID BAG WILL SLIDE OFF OF SAID HORIZONTAL SPOUT.