US3749142A - Bag settler for bag filling machines - Google Patents

Abstract

The saddle member of a settler is mounted on a lever fulcrumed on a mounting plate assembly. The other end of the lever is connected to a vertically reciprocating crank rod. The crank rod is driven from a drive shaft by an eccentric cam mounted on the drive shaft and a yoke on the crank rod so that it reciprocates with a harmonic motion. Interposed between the lever end and the crank rod are two springs, one located above the lever and one below. The springs tend to absorb a portion of the reciprocating motion of the crank, the amount of absorption being greater of the bag weight increases. Thus a smaller amount or vibration is transmitted to the bag as it approaches its filled condition thus improving the operation of the scale mechanism of the bag filling machine.

Description

[451 July 31, 1973 [5 4] BAG suntan ron BAG FILLING MACHINES [751 investors rfiv'ih'mnau;mm

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[22] Filed: Apr. 16, 1971 [21] Appl. No.; 134,575

[52] US. Cl 141/73, 141/83, 141/114, 141/315, 177/118, 259/D1G. 42 [51] Int. CL... .Q. B651) [/22 [58] Field of Search", 73/242.13 R; 141/68, I 141/71, 73-77, 83,114, 315; 177/118; 259/72, DIG. 42

FORElGN PATENTS OR APPLICATIONS 936,255 12/1955 Germany 141/76 Primary Examiner-llouston S. Bell, Jr. Attorney-label Baker York and Jones ABSTRACTv The saddle member of a settler is mounted on a lever fulcrumed on amounting plate assembly. The other end of the lever is connected to a vertically reciprocating crank rod. The crank rod is driven from a drive shaft by an eccentric cam mounted on the drive shaft and a yoke on the crank rod so that it reciprocates with a harmonic motion. lnterposed between the lever end and the crank rod are two springs, one located above the lever and one below. {1' he springs tend to absorb a portion of the reciprocating motion of the crank, the amount of absorption being greater of the bag weight increases. Thus a smaller amount or vibration is transmitted, to the bag as it approaches its filled condition thus improving the operation of the scale mechanism of the bag filling machine.

Patented Jul '31, 1973 3,749,142

3 SheetsSheet 1 .1 g 3 INVENTOR ERWIN M. L u

WM'YS Patented July 31, 1973 3,749,142

3 Sheets-Sheet 2 Q QQQ INVENTOR ERWIN M. LAU

I Z WW'YS Patented Jul 31, 1973 3,749,142

- 3 Sheets-Sheet 3 IN VE N TOR ERW/N M. LAU

BYW

ATT'YS BAGSETTLER FOR BAG FILLING MACHINES This invention relates to a bag settling device for bag filling machines. In such devices, the settling action is obtained by vibrating a saddle on which the bag rests as it is being filled.

The bag filling machine is one having a spout which is received within the valve of a valve type bag, and the bag is partially supported from the spout and partially supported by the saddle, both being connected to scale mechanism. When the contents of the bag reaches a predetermined weight, such as 100 pounds, the scale mechanism trips and terminates the filling operation.

1 BACKGROUND OF THE INVENTION It has been found that the vibration of the bag and bag contents interferes with the uniform terminating action of the scale mechanism. This is due to the fact that the vibrations are transmitted to the scale mechanism, partly through the spout, and partly due to the reaction of the saddle.

As pointed out in my earlier U.S. Pat. No. 3,1 15,905, patented Dec. 31, 1963', these vibrations may also be transmitted to the bearing points of the scale mechanism causing damage or undue wear.

The problem of interference with theoperation of the weighing mechanism was recognized in Douglas U.S. Pat. No. 2,981,349, but the solution proposed,

that of dynamically balancing the drive shaft with counter weights, does not constitute an effective solution because it in no way reduces the magnitude of the vibrations transmitted'by the bag to thespout.

Certainaspects of the problem were also recognized inVredenburg, U.S. Pat. No. 2,602,626 in which it was SUMMARY OF THE INVENTION I have found that by coupling the driving means to the vibrating system through a double acting resilient means that the vibration of the bag reduces in magnitude as the bag approaches the filled condition. The double actingresilient means increases the isolation of the saddle from the drive means as the mass of the oscillating system comprising the saddle and the bag contents is increased when the bag is being filled. In the construction shown herein, the vibratory force on the bag at this time can hardly be detected by the operators hand. Thus, although vibrations of substantial magnitude are transmitted to the bag contents during the early stages of the filling cycle, as it approaches the end of the filling cycle, the vibrations are reduced to an extent where they do not interfere with the operation of the scale mechanism and furthermore, no damage or unduewear of the bearingpoints occurs. l have found that the accuracy of my improved bag filling machine is substantially the same as that ofa machine in which the settler mechanism is eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a front elevation of a bag filling machine embodying my invention;

FIG. 2 is an enlarged front view of the settler device;

FIG. 3 is a plan view taken along line 3-3 of FIG. 2;

FIG. 4 is a side elevation of the settling device;

FIG. 5 is a plan section taken along line 5-5 of FIG. 4 with the saddle flanges omitted;

FIG. 6 is a vertical section taken along line 6-6 of FIG. 3;

FIG. 7 is an enlarged detail view of a portion of FIG. 6, with the collar shown in section; and

FIG. 8 is a section taken along line 8-8 of FIG. 4 showing a detail.

The reference numeral 10 in FIG. 1 indicates a bag filling machine on which is mounted a settler 18. The bag filling machine 10 comprises a framework 11 which supports a hopper or chamber 12 for receiving material to be packed into bags. It also includes a spout 13 which is mounted on a floating frame 14. The machine shown is an auger type of machine and the construction of the floating frame and the elements of the scale mechanism is shown in Lau U.S. Pat. No. 3,301,340 granted Jan. 31, 1967. However, the invention is applicable to other types of bag filling machines. In th particular construction shown, the floating frame 14 is supported by leaf springs, not shown, from an element rigidly associated with the framework 1], and suitable flexible conduit means, not shown, connect the spout 13 with the interior of the hopper 10 so that the spout and the floating frame 14 are free for relative movement with respect to the framework 11 to actuate suitable scale mechanism 15.

The scale mechanism includes a fulcrum bar 16 fixed with respect to the framework 1 I which engages a scale beam 17. Leaf springs 14a connect the floating frame 14 to the scale beam 17 so thatwhen the weight of the contents of a bag supported from the floating frame 14 reaches a predetermined amount, such as 100 pounds, the scale mechanism will be tripped to discontinue the filling action.

A pair of hanger rods 19 are screwed to the front face of a plate 20, forming a part of the floating frame 14. The hanger rods include hook portions 21, shown in FIG. 4, which hook over the top of the plate 20. The exact means for connecting the hanger rods to the scale mechanism varies with different types of scale construction.

The hanger rods 19 each have a series of holes 22 so that the settler 18 can be mounted at various elevations, depending upon the length of the bag to be filled, and which is supported from the spout 13.

The settler 18 comprises a mounting plate assembly 23 (FIG. 5) providing two pairs of plates, each pair comprising an inner plate 24 and an outer plate 25. The plates are maintained in horizontally spaced relationship by one or more horizontal pillars 26.

There are two U-shaped brackets 27 mounted on each of the outer plates 25, as shown in FIGS. 2, 4 and 5. Each upper bracket has a nut 28 welded to it and a hand screw 29 extends through the nut and the bracket into one of the holes 22 of a hanger rod 19.

No screw is required for the lower bracket 27, which merely serves to define the relative positions of the hanger rod and the mounting plateassembly. Thus, by

removing the two hand screws 29 the vertical position of the settler 18 can be adjusted.

The outer plates 25 are each provided with a flange 30 to each of which a flanged bracket 31 is secured, as shown in FIG. 5. The outer ends of the brackets 31 support a vertical plate 32 which serves as a mount for a motor 33. The latter drives a shaft 34 through a belt 35 and suitable pulleys.

A bearing block 36 is mounted on the lower end of the flanges 30, and the shaft 34 is journaled at either end in the bearing blocks 36, as shown in FIG. 5.

Two eccentric-type earns 37, one being shown in FIG. 6, are mounted on and keyed to the shaft 34. The cams drive the yoke 38 of a reciprocating drive member in the form of a crank rod 40 through suitable ball bearing units 39. The crank rod 40 vibrates the saddle 41 by means hereinafter described.

In the embodiment shown, the machine is provided with two saddle members 41, although a single saddle member may be used if desired. Since the separate drive mechanisms for each saddle member are substantially identical to each other, the same reference numerals are applied to the corresponding parts of each, and only one is described herein. Each saddle member 41 has a side flange 42 and an inner depending flange 43, as shown in FIG. 2. The two inner flanges 43 are spaced from each other to receive the seam of the bag being filled.

Each saddle member has two depending arms 44 which are pivotally connected to a lever 45 which is fulcrumed on a shaft 46 mounted in the mounting plate assembly 23. A second shaft 47 provides a pivotal connection between the depending arms 44 and the outer end of the lever 45. Each lever 45 has two hub portions 48, one for the shaft 46 and one for the shaft 47. For each hub, which is in the form of a hollow cylinder, there are two flanged hard rubber bushings 49, which receive the respective shaft 46 or 47. The shaft is headed at one end and is threaded to receive a nut at the other so that the various parts are retained in operating relationship.

A link 50 also connects the depending arms 44 with the plate assembly 23, by means of pivoted connections 51 which are the same as the shaft, the hub portions and the flanged bushings above described. Thus the 4 lever 45 and the link 50 together with the elements 44 and 23 comprise a linkwork which maintains the arms 44 always in a vertical position during oscillation of the saddle member 41, as hereinafter described.

The inner end of the lever 45 terminates in a collar 53 having a centrally inwardly directed flange 54, as shown in FIG. 7. The crank rod 40, which is threaded, extends through the collar 53, and upper and lower springs 55 and 56 respectively, surround the rod 40 and are confined between nuts 57 and the flange 54. The springs 55, 56 together with elements 40, 53 and 57, comprise a double acting spring assembly 60 which is preloaded so as to provide a self restoring action on the collar 53.

In operation, movement of the crank rod 40 upwardly is resisted by the difference between the forces exerted by the upper and lower springs 55, 56, as is movement of the crank rod 40 in the downward direction. At all static conditions of bag weight, the collar 53 will seek a position of equilibrium in which the net force exerted by the springs 55, 56 balances the weight of the bag contents, which means that as the bag ap- 3 bottom spring 56 if the pinters 59 read equal vvalues due to the net weight of the saddle assembly which includes elements 41, and 50.

In operation, a bag, not shown, is fitted over the spout 13. Then the machine 10 is turned on which causes material to be fed through the spout and into the bag, and at the same time, the saddle members 41 are vibrated. When the bag is almost empty, the vibrating movement of the bag and contents will not cause any appreciable force to be transmitted to the spout l3, and thence to the floating frame 14. This is due to the slackness of the bag. However, as the bag approaches filled condition, the bag walls fill out and would ordinarily transmit vibrations to the spout 13. Additionally, there is a certain reaction of the saddle member 41 against the bag, which reaction would tend to be transmitted through the mounting plate assembly 23 to the hanger rods 19 and the floating frame 14.

These forces acting on the floating frame 14, unless reduced by the spring isolation means described herein, will cause a nonuniform operation of the scale mechanism from one filling operation to the next, because a net downward force applied to the floating frame 14 will cause the scale mechanism to trip prior to the time intended, and a net upward force would tend to delay the tripping, this variation in accuracy being as much as a pound in either direction in the case of a 100 0 pound bag.

However, according to my invention, as the bag approaches its filled condition, the double acting spring assembly 60 reduces very substantially the magnitude of the vibratory force transmitted to the bag. Assuming 5 a pound bag, the net vibratory force on the bag can hardly be detected by the operators hand, and it is estimated that its force is only about one-tenth of the vibratory force which is transmitted to the bag contents in the early stage of the filling operation. The reaction is corresondingly reduced.

I have found that the accuracy of the scale mechanism according to my invention, is substantially the same as if the settler mechanism were eliminated. Nevertheless, the bag contents are effectively settled to provide the desired density of packing.

The two eccentrics 37, when offset from each other by I80", exert a certain counterbalancing action with respect to each other. However, I prefer to provide a separate eccentric counterweight 61 for each eccentric cam 37. Each is keyed to the shaft 34, offset from its associated eccentn'c cam 37, according to standard practice. Also, the use of the counterweights permit the two eccentric cams 37 to be operated in phase with each other, or at any other desired phase relationship. The counterweights 60 and eccentrics 37 are spaced from each other and from the bearings 36 by means of suitable spacers 62, as shown in FIG. 5.

and engages the plate 32 through nuts 65 so that the belt tension may be adjusted. Also, by removing the nuts 65, the plate 32 and the motor 33 may be swung out, after the belt has been removed, giving access to the nuts 57 by means of which the spring tension of the double acting spring assembly 60 may be adjusted. As shown in FIG. 8, the T-bolt 64 includes a cross head 65 located between the inner plates 24 and pivotally secured thereto by screws 66.

In a practical embodiment of my invention, the shaft 34 is driven at 1800 RPM. The eccentricity of earns 37 is rs-inch radius, giving a Kr-inch amplitude of vibration, the arms of lever 45 being of equal length.

The springs 55 and 56 are Rambler automobile valve springs Part No. VS 768 having an overall length of 2% inches. On a compression test, the application of 25 pounds pressure reduced the length by /a-inch, thus giving an elastic spring constant of 200 pounds per inch deflection for each spring. The weight of each saddle assembly, comprising elements 41, 45, 50, is about pounds.

Although only a preferred embodiment of my inven- .tion has been shown and illustrated herein, it will be understood that various modifications and changes can be made in the construction shown without departing from the spirit of my invention, as pointed out in the appended claims.

I claim:

l. A bag filling machine comprising scale mechanism responsive to the weight of the contents of a bag being filled for terminating the filling cycle of said bag filling machine, a settler for vibrating a bag as it is being filled, and means for suspending said settler from said scale mechanism, said settler comprising a saddle assembly, a reciprocating drive member therefor, and means for supporting said saddle assembly on said suspending means, said saddle assembly including a saddle member engaging the bottom of said bag and a member connecting said saddle member and said drive member, means for imparting harmonic reciprocating motion to said drive member, and double acting resilient means interposed between said drive member and said connecting member for increasing the isolation of said saddle assembly from said drive member as the mass of the oscillating system comprising said saddle assembly and said bag contents is increased when said bag is being filled.

2. A bag filling machine as claimed in claim 1 in which said connecting member is a horizontally disposed lever, said harmonic motion imparting means comprises an eccentric cam, and said drive member comprises a vertically disposed crank rod having a yoke engaging said eccentric cam.

3. A settler for use in a weighing type bag filling machine comprising a body member adapted for connection to the scale mechanism of said bag filling machine, a lever pivoted in said body member, a saddle member pivotally connected to one end of said lever, a reciproeating drive member connected to the second end of said lever, means for imparting harmonic reciprocating motion to said drive member to vibrate said saddle member, anddouble acting resilient means interposed between said drive member and said second end of said lever for increasing the isolation of said saddle member from said drive member as the load on said saddle is increased by the increase in the weight of the contents of a bag supported by said saddle member.

4. A settler as claimed in claim 3, in which said saddle member includes a depending arm, said lever being pivotally connected to said saddle member at said depending arm, and a link member spaced from said lever and disposed parallel thereto and extending between said body member and said depending arm and forming with said lever, depending arm, and body member, a linkage whereby said saddle is maintained in an upright position.

5. A settler as claimed in claim 3 in which said harmonic motion imparting means includes a drive shaft,

an eccentric cam on said drive shaft, said reciprocating drive member including a yoke surrounding said eccentric cam, and a motor for driving said drive shaft.

6. A settler as claimed in claim 5 which includes a motor mounting plate pivotally mounted at its upper end on said body member, releasable means for securing the lower end of said motor mounting plate to said body member whereby said motor mounting plate can be swung upwardly and away from said reciprocating drive member to provide access to said resilient means.

7. A settler as claimed in claim 3 which includes a collar mounted on said second end of said lever, said reciprocating drive member extending through said collar, two adjusting nuts threaded on to said drive member, one being above said collar and one being below said collar, said double acting resilient means comprising a pair of coil springs, one being confined between said collar and said upper nut, and the other being confined between said collar and said lower nut whereby said springs resist relative axial motion between said collar and said drive member in both axial directions.

8. A settler for use in'a weighing type bag filling machine comprising a mounting plate assembly adapted for connection to the scale mechanism of said bag filling machine, two horizontally disposed levers pivoted side by side in said mounting plate assembly, two saddle members each being pivotally connected to the outer end of one of said levers, two vertically reciprocating drive members each being connected to the inner end of one of said levers, eccentric means for imparting harmonic reciprocating motion to each drive member to vibrate said saddle members in opposed phase relationship, and double acting resilient means interposed between each drive member and its associated lever for increasing the isolation of each saddle member from its associated drive member as the mass of the oscillating system comprising said two saddle members and the contents of a bag supported thereby is increased when said bag is being filled.

$ t i t

Claims (8)

1. A bag filling machine comprising scale mechanism responsive to the weight of the contents of a bag being filled for terminating the filling cycle of said bag filling machine, a settler for vibrating a bag as it is being filled, and means for suspending said settler from said scale mechanism, said settler comprising a saddle assembly, a reciprocating drive member therefor, and means for supporting said saddle assembly on said suspending means, said saddle assembly including a saddle member engaging the bottom of said bag and a member connecting said saddle member and said drive member, means for imparting harmonic reciprocating motion to said drive member, and double acting resilient means interposed between said drive member and said connecting member for increasing the isolation of said saddle assembly from said drive member as the mass of the oscillating system comprising said saddle assembly and said bag contents is increased when said bag is being filled.

2. A bag filling machine as claimed in claim 1 in which said connecting member is a horizontally disposed lever, said harmonic motion imparting means comprises an eccentric cam, and said drive member comprises a vertically disposed crank rod having a yoke engaging said eccentric cam.

3. A settler for use in a weighing type bag filling machine comprising a body member adapted for connection to the scale mechanism of said bag filling machine, a lever pivoted in said body member, a saddle member pivotally connected to one end of said lever, a reciprocating drive member connected to the second end of said lever, means for imparting harmonic reciprocating motion to said drive member to vibrate said saddle member, and double acting resilient means interposed between said drive member and said second end of said lever for increasing the isolation of said saddle member from said drive member as the load on said saddle is increased by the increase in the weight of the contents of a bag supported by said saddle member.

4. A settler as claimed in claim 3, in which said saddle member includes a depending arm, said lever being pivotally connected to said saddle member at said depending arm, and a link member spaced from said lever and disposed parallel thereto and extending between said body member and said depending arm and forming with said lever, depending arm, and body member, a linkage whereby said saddle is maintained in an upright position.

5. A settler as claimed in claim 3 in which said harmonic motion imparting means includes a drive shaft, an eccentric cam on said drive shaft, said reciprocating drive member including a yoke surrounding said eccentric cam, and a motor for driving said drive shaft.

6. A settler as claimed in claim 5 which includes a motor mounting plate pivotally mounted at its upper end on said body member, releasable means for securing the lower end of said motor mounting plate to said body member whereby said motor mounting plate can be swung upwardly and away from said reciprocating drive member to provide access to said resilient means.

7. A settler as claimed in claim 3 which includes a collar mounted on said second end of said lever, said reciprocating drive member extending through said collar, two adjusting nuts threaded on to said drive member, one being above said collar and one being below said collar, said double acting resilient means comprising a pair of coil springs, one being confined between said collar And said upper nut, and the other being confined between said collar and said lower nut whereby said springs resist relative axial motion between said collar and said drive member in both axial directions.

8. A settler for use in a weighing type bag filling machine comprising a mounting plate assembly adapted for connection to the scale mechanism of said bag filling machine, two horizontally disposed levers pivoted side by side in said mounting plate assembly, two saddle members each being pivotally connected to the outer end of one of said levers, two vertically reciprocating drive members each being connected to the inner end of one of said levers, eccentric means for imparting harmonic reciprocating motion to each drive member to vibrate said saddle members in opposed phase relationship, and double acting resilient means interposed between each drive member and its associated lever for increasing the isolation of each saddle member from its associated drive member as the mass of the oscillating system comprising said two saddle members and the contents of a bag supported thereby is increased when said bag is being filled.

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