US3900055A

US3900055A - Bag packing apparatus

Info

Publication number: US3900055A
Application number: US433638A
Authority: US
Inventors: Allan L Henry
Original assignee: Stauffer Chemical Co
Current assignee: Stauffer Chemical Co
Priority date: 1974-01-16
Filing date: 1974-01-16
Publication date: 1975-08-19
Anticipated expiration: 1992-08-19

Abstract

A bag packing apparatus is described having an operating cycle which includes a fill mode of operation and a dwell mode of operation. A powdered or finely granulated material which is to be bagged is contained in a storage means and an elongated material outlet spout communicates with the storage means. Means are provided for conveying the material from the storage means to the spout and for causing the material to flow from the spout. The apparatus further includes a means for supplying and positioning an empty bag about the spout and for discharging a filled bag from the spout during a dwell mode of operation. A first material flow control means cyclically enables the discharge of material from the spout into the bag during the fill mode and disables the flow of material from the spout during the dwell mode. A second material flow control means is also provided including a switch which is positioned at the spout and is adapted for engagement by a bag which is positioned at the spout. The second material control means is arranged for disabling the flow of material after the initiation of the fill mode when a bag becomes disengaged from the switch.

Description

United States Patent 11 1 1111 3,900,055

Henry Aug. 19, 1975 BAG PACKING APPARATUS ating cycle which includes a fill mode of operation and dwell mode ofo eration. A owdered or finel ran 75 1 t Alla L.Henr N E'l,P'. P P Yg or n cw 6 d ulated material which 15 to be bagged is contained in a [73] Asslgneei al e Chemical p y. storage means and an elongated material outlet spout WBStPOFt, COnflcommunicates with the storage means. Means are pro- [22] Filed: Jam 16,1974 vided for conveying the material from the storage means to the spout and for causmg the material to [21] Appl. No.: 433,638 flow from the spout. The apparatus further includes a means for supplying and positioning an empty bag 52 US. Cl 141/67; 141/281 about the and for discharging filleid bag from [5]] Int Cl 1365b U04 the spout durmg a dwell mode of operat1on. A first 58 Field of Search 141/10, 67, 68, 83, 13, material flow m means W enables the l 141/1564 62 184, 192, 2088 269, 281 charge of matenal from the spout into the bag durmg the fill mode and disables the flow of material from the spout during the dwell mode. A second matenal [56] References Cited flcgw lclzontrol l'neans ist alllso provtideiinclvdirlgciifswitch w 1c 1s pos1 lone a e spou an 1s a ap e or en- UNITED STATES PATENTS gagement by a bag which is positioned at the spout. KlfldSCtl'l The econd material control means is arranged for dis 3,750,72l 8/l973 Hudson 141/10 abling the flow of material after the initiation of tha Primary Examiner-Houston S. Bell, Jr.

[57] ABSTRACT A bag packing apparatus is described having an operfill mode when a bag becomes disengaged from the switch.

6 Claims, 6 Drawing Figures 1 I l l PATENTEB AUG"! 91975 SHEET 1 BF 4 PATENTED AUBI 9 1975 PATENTEU Ans-1 9191s w NR BAG PACKING APPARATUS This invention relates to apparatus for filling bags with granular or powdered material. The invention relates more particularly to improvements in bag packing apparatus which enhance the efficiency and safety of operation of the apparatus.

A method for bagging a powdered or finely granulated material is known wherein the material is supplied through a horizontally extending spout from a hopper to a bag which is positioned partly about the spout. In a particular method, a valve bag is employed as a receptacle. A typical valve bag employed for this use includes a self-sealing flap valve located in one corner of the bag. The flap valve is adapted to be penetrated by the filler spout which extends through the valve into an upper interior section of the bag. During a filling mode of operation, the bag is supported from the spout or on a bag chair or is supported simultaneously by the spout and the bag chair. Material which is to be bagged is delivered by fluidizing the material with a gaseous medium and conveying the fluidized material under pressure from a hopper to the bag. Alternatively, the material is conveyed by mechanical means from the hopper to the bag. One such mechanical arrangement utilizes an auger which extends through the spout from the material supply. Rotation of the auger causes the material to progress through the spout from the supply to the interior of the bag. Either the spout, or the bag chair, or both, operate to actuate a weighing means which is coupled to a control system for automatically interrupting the flow of the material to the bag when the gross weight of the bag attains a predetermined magnitude. In an automated system of this type, the valve bags are automatically removed from a magazine and are sequentially positioned upon the filler spout of the packer apparatus. Each bag is then filled, removed from the spout and deposited on a conveyer belt which transports the filled bag to a stacker.

Known packing arrangements for filling valve bags with powdered or finely granulated materials have exhibited limitations which undesirably reduce the efficiency of the packing operation, increase operator discomfort, and introduce a potential explosion danger. A significant loss of material occurs when the material flows directly from the spout in the absence of the valve bag at the spout or in the absence of a properly positioned valve bag at the spout. All or a portion of a quantity of material for filling a bag will then be discharged from the spout into the atmosphere. This faulty condition can arise for a number of reasons including a malfunction in the automatic bag feeding device, a malfunction in a bag clamping device, etc. In addition, in a fluidized material bagging arrangement, the pressure of the fluidized material may be at times suffi cient in magnitude to blow or discharge the bag from the spout before the bag is filled.

The loss of material during the filling operation generally results in a significant dispersion of material in the atmosphere about the apparatus. The loss not only results in an increase in the unit cost of filling each bag, but the dispersion of the powdered material in the at mosphere about the apparatus increases the operator discomfort and creates a health hazard to machine operators working in the immediate area. Furthermore, the dispersion of a powdered material in the atmosphere about the machine can create a condition whereby a dust explosion can occur. It is therefore desirable to provide means for inhibiting the loss of powdered material from the spout.

In attempting to overcome these limitations. there has been provided a bag actuated switch which is arranged for inhibiting the initiation ofa fill mode of operation unless a bag is positioned on the spout and a bag clamp engages the bag at the spout. Nonetheless. with a bag actuated switching means which initiates the filling mode of operation, a defective operation of the clamping means can subsequently result in discharge of a bag and the undesired flow of material into the atmosphere.

Accordingly, it is an object of this invention to provide an improved bag packing apparatus.

Another object of this invention is to provide an improved apparatus for packing valve bags with a powdered or finely granulated material.

Another object of the invention is to provide an apparatus for packing valve bags which enhances the efficiency and reduces the cost of operation, reduces the human discomfort and danger to health in the environment about the apparatus, and reduces an explosion hazard accompanying the dispersion of material in the atmosphere.

A more particular object of the invention is to provide a bag packing apparatus which inhibits the flow of a material from a filler spout when a valve bag is not positioned or is improperly positioned on the filler spout.

Another more particular object of the invention is to inhibit the flow of material from a filler spout when a valve bag is discharged from the filler spout during a fill cycle.

Another object of the invention is to provide a bagpacking apparatus which inhibits the discharge of a partially filled bag from the apparatus.

In accordance with features of this invention, a bagpacking apparatus is provided having an operating cycle which includes a fill mode of operation and a dwell mode of operation. A powdered or finely granulated material which is to be bagged is contained in a storage means and an elongated material outlet spout communicates with the storage means. Means are provided for conveying the material from the storage means to the spout and for causing the material to flow from the spout. The apparatus further includes a means for supplying and positioning an empty bag about the spout and for discharging a filled bag from the spout during a dwell mode of operation. A first material flow control means cyclically enable the discharge of material from the spout into a bag during the fill mode and disables the flow of material from the spout during a dwell mode. A second material flow control means is also provided including a switch which is positioned at the spout and is adapted for engagement by a bag which is positioned at the spout. The second material control means is arranged for disabling the flow of material after initiation of the mode fill when a bag becomes disengaged from the switch.

These and other objects and features of the invention will become apparent with reference to the following specification and to the drawings wherein:

FIG. 1 is a side elevation view, partly broken away, illustrating a bag-packing apparatus constructed in accordance with features of this invention;

FIG. 2 is an enlarged view of a portion of the apparatus of FIG. 1 taken along lines 22 and illustrating a bag fill spout for the apparatus;

FIG. 3 is a right hand view of the fill spout of FIG. 2;

FIG. 4 is a further enlarged exploded perspective view of the fill spout of FIG. 1 illustrating a bag actuated switching means;

FIG. 5 is a block diagram illustrating a means for controlling the apparatus of FIG. 1 in a cyclic manner; and

FIG. 6 is a schematic diagram of the control means of FIG. 5.

The apparatus of FIG. 1 is adapted for repeatedly progressing through an operating cycle during which cycle a bag 7 is positioned on a filler spout 8, material is discharged into the bag until the bag contains a predetermined weight, and the filled bag is discharged from the spout to a conveyor 9 for transport to a bag stacker. The apparatus cycle includes a fill interval during which the apparatus operates in a fill mode and performs functions directed to filling a bag with material and a dwell interval during which the apparatus operates in a dwell mode and performs functions directed to replenishing the apparatus for performance of a succeeding fill mode.

Material I0 which is to be bagged and which is stored in an upper hopper ll periodically flows through the operation of a valve 12 to an intermediate storage means comprising a chamber or bin 13. During the operational cycle, the valve 12 is operated by a lever arm assembly 16 and which in turn is pneumatically actuated by a piston of a piston and cylinder assembly 18. As viewed in FIG. I, the upward motion of the piston of this assembly causes counterclockwise rotation of the valve 12 thereby enabling the flow of material from the hopper 11 to the chamber 13. The valve 12 is actuated during a dwell mode while during a fill mode, the valve 12 is seated and provides a pressurized seal for the chamber.

The elongated spout 8 is mounted to the apparatus and communicates with the interior of the chamber 13. Material which is positioned within the chamber 13 flows through the spout and the effluent of the spout is introduced into a bag 7 which is positioned on the spout. The flow of material through the spout 8 occurs during a fill mode of operation and is controlled by a resilient, tubular pinch valve 24 (FIGS. 2 and 3) which is positioned near an inlet aperture of the spout. The tubular valve 24 which is formed of rubber or other suitable material is illustrated in FIGS. 2 and 3 in an open position. The resilient valve is normally open and is pinched to a closed position by a ram 27 which is actuated by a piston 26 of a piston and cylinder assembly 28. As the piston (FIG. 3) of the assembly 28 is advanced, the valve 24 closes and provides a seal for the chamber 13.

A means for conveying material from the chamber 13 to the spout 7 and for causing the material to flow from the spout is provided. A source of pressurized inert gas 30 is coupled to a lower section of the chamber 13 through a line 32, a flow control 33 and a line 35. This flow of gas fluidizes the material in the chamber 13. In addition. inert gas for pressurizing the chamber is coupled to the chamber 13 via a line 32, a valve assembly 34 and a line 36. At the initiation of the fill mode, the valving means 34 is enabled and permits the inert gas to flow and pressurize the chamber 13. The material which has been deposited in the chamber 13 becomes fluidized by flow through line 35 and comprises a powdered or finely granulated material dispersed in an inert carrier gas. Upon initiation of the fill mode of operation, the valve 24 is opened and the fluidized material under pressure flows from the chamber 13 through the spout to the interior of the bag 7.

The elongated spout 8 is adapted for extending into a bag 7 which is positioned thereon. In the bagging apparatus illustrated in FIG. I, a bag feeder 39 is provided for automatically conveying to and positioning a bag upon the spout 8. The bag feeder 39 includes a magazine 40 which advances bags in a direction out of the paper, as viewed in FIG. I, to a bag feed discharge station. At the bag feed discharge station, a frame assembly 42 having a plurality of pneumatically energized suction cups 44 mounted thereon is advanced into contact with a bag at the discharge station. The frame 42 is activated by piston 46 which extends from a cylinder 48. The cylinder 48 is positioned on a reciprocating transport table 50. As the table 50 advances in a direction into the paper as viewed in FIG. I, the suction cups 44 contact a bag located at the bag feed discharge station. The cups are then pneumatically energized thereby grasping a bag. When a bag is thus secured, the table 50 reverses direction of movement and advances in a direction out of the paper, as viewed in FIG. 1, until the bag is aligned with the spout 8. The piston 46 is then extended and the bag is transported laterally until it is positioned about the spout 8. Suction cups 44 are then de-energized thereby releasing the bag while a piston 51 (FIG. 2) extends from a cylinder 52 to contact the bag, and to establish a holding force on the bag against the spout 8.

The bags 7 which are delivered from the magazine 40, preferably comprise valve bags which, as is known, include a valve in an upper corner thereof which is dimensioned and adapted for permitting penetration by the spout 8. Since the spout is maintained stationary, the valve bag feeder 39 orientates the valve with respect to the spout and slides the bag onto the spout so that the spout extends into the interior of the bag. In addition, a lower portion of the bag is positioned with respect to a V-shaped bag chair and as the bag becomes filled with material, the weight of the bag is principally supported by the bag chair. A sensing means 62 is provided for sensing when the gross weight of the bag and its contents attains a predetermined magnitude. When this weight is attained, a bleeder valve is energized which, as indicated in greater detail hereinafter, initiates the transition of the operating cycle from a fill mode to a dwell mode. Alternatively, a portion of the weight of the bag is supported by the bag chair 60 while a portion is also supported by the spout 8. The spout and bag chair are colinked for providing actuation of a bleeder valve when the gross weight of the bag attains a predetermined magnitude.

A transition from a fill to a dwell mode is accompanied by an actuation of the valve 24 which becomes closed and inhibits further flow of the material from the spout 8. The bag clasping piston SI is withdrawn and a bag discharging piston cylinder assembly 64 is energized and causes a ram 66 which is mounted on a piston of the assembly to advance and force the filled bag 7 from the spout and onto a moving conveyor belt 68 of the conveyor 9. During the dwell mode, the valve 12 is again actuated after a timed delay for permitting a quantity of material sufficient for filling one bag to be deposited in the chamber 13. The valve 12 remains actuated until transfer to the fill mode. A replacement bag is removed from the magazine and is positioned on the spout 8 and the apparatus is again conditioned for a repeated fill mode of operation.

A pneumatic control system for controlling the oper ating cycle of the apparatus of FIG. I will be described with reference to the functional block diagram of FIG. 5. The pneumatic control system illustrated in FIG. 5 includes a bi-stable fill cycle control valve 70 which is coupled to a plurality of valve means 34, 74 and 76 (and valve 78 is indicated below) each of which is adapted for energizing associated elements of the bagging apparatus. The valve means 34 is adapted for controlling the pressurization and venting of the chamber 13 at appropriate times during the operating cycle as is indicated hereinafter. A purge, clean-out, and expansion sleeve air flow valving means 74 is adapted for controlling the flow of air to the fill spout 8 in order to maintain it in an unblocked condition and for providing an enhanced seal, between the spout 8 and bag 7 as indicated hereinafter. The valving means 76 is adapted for energizing or de-energizing the piston cylinder assembly 18 thereby controlling the feed gate valve 12.

A bag clamp and discharge valve means 78 is arranged for energizing and de-energizing the piston 51 and cylinder 52 assembly for clamping the bag to the spout 8 and for energizing and de-energizing the piston and cylinder assembly 64 for discharging a bag 7 from the spout 8. Valving means 78 is operated under control of the fill cycle control valve 70. However, in order to inhibit the discharge ofa partially filled bag when a fill mode of operation is terminated before routine completion of the fill mode, the control of the valve means 78 is conditioned on the state of a control gate 84. In addition, the fill cycle control valve further operates to energize and de-energize the piston and cylinder assembly 28 for providing direct control of the flow cut-off valve 24. Bag clamping and discharge valving means 78 also provides a signal to the bag applicator 39 for enabling the initiation of a bag supplying sub-cycle.

An operational cycle as indicated hereinbefore includes a dwell mode and a fill mode. The apparatus is normally in dwell mode and when operation thereof is initiated, by actuation by an operator of a manual switching means 80, the fill cycle control valve 70 is switched and causes transition of the apparatus from the dwell to the fill mode. When the fill cycle control valve is thus switched by operation of the manual starter valve 80, a bistable bag discharge control valve 82 is simultaneously actuated thereby enabling the gate valve 84 and allowing the fill cycle control valve means 70 to actuate the bag clamp and discharge valve means 78 at a subsequent point of time during a cycle. When operation of the apparatus is thus initiated, the described valve switching means causes the bag clamp piston 51 to extend and grip a bag 7 at the spout 8, the feed gate valve 12 to close, the chamber 13 to become pressurized with inert gas, the flow of-a low pressure purge gas through the spout to be initiated. and the feed gate 24 to be actuated thereby permitting flow of the fluidized material from the chamber 13, to the bag. The material continues to flow from the spout until the gross weight of the bag attains the predetermined weight.

A dwell mode is automatically initiated when the bag chair or spout or combination thereof actuates a scale stop bleeder valve 86. Actuation of this valve causes the fill cycle control valve to reset. This accordingly closes the flow cutoff valve 24 causing the interruption in flow of the material from the spout 8. The interruption in the pressurization of the chamber 13 and a momentary venting thereof, the interruption of the low pressure air flow to spout 8 and the activation of the clean-out switching valve means for causing the momentary flow of air under full pressure to the spout and into the bag, the actuation of the feed gate valve 12, after a delay, to an open position, the retraction of the piston 51 ofthe bag clamp, the actuation of the bag discharge piston of assembly 64 causing the discharge of the bag from the spout, and the initiation of the bag applicator sub-cycle whereby a bag is positioned at the spout 8. The apparatus is adapted for repeated cycling through the use of an automatic start valving means 87 which is actuated by the bag applicator 39. In particular, the transport frame 42 which transports a replacement bag to the spout is adapted for engaging and actu ating an automatic start valve 87 which causes the switching of the fill cycle control valve 70 and resets the bag discharge valve 82 as indicated hereinbefore. The apparatus is switched into a fill mode and thereby continues to recycle.

FIG. 5 as described illustrates a material flow control means for cyclically enabling the discharge of material from the spout 8 into a bag 7 during a fill mode of operation and for disabling the flowof material from the spout during a dwell mode of the operation. In addition, and in accordance with a feature of this invention, a second material flow control means including a switch position at the spout for engagement by a bag which is positioned on the spout is provided and is arranged for disabling the flow of material during a fill interval of the operating cycle upon disengagement of the bag from the switch. Thus. when a bag is blown from the spout by virtue of the fluidized material pressure, or when the bag becomes improperly positioned upon the spout during the fill interval, the flow of material from the spout which would otherwise contaminate the atmosphere about the apparatus is automatically inter rupted.

Referring now to FIG. 4, the spout 8 is shown to have positioned thereon an expansion sleeve 88 to which the flow of air is directed during a fill cycle for enhancing the seal between the spout and the valve bag. A contact plate 90 is positioned partly about the spout and includes an arcuate segment 92 which conforms to the shape of the expansion sleeve or alternatively, in the absence of an expansion sleeve, to the shape of the fill spout 8. Rods 94 and 96 are secured to the plate 90 and are adapted for extending through apertures formed in

support angle sections

98 and 100, respectively. Coil springs 102 and 104 are positioned about the rods 94 and 96 respectively and are provided for mechanically biasing the plate 90, in a forward direction along the spout. The rods 94 and 96 are restrained from escaping under the force of the springs from the rearmost apertures of the plates 98 and by cotterpins which extend through bores formed in each of the rods. The plate is movable along the spout upon engagement by a bag which causes the plate to move inward along the spout against the pressure of the

springs

102 and 104. A guide 105 is mounted to the plate 90 and extends forward of the plate. The guide includes a distal segment 107 which curves toward the spout 8. This guide operates to inhibit the edge of a bag upon positioning on the spout from entering a clearance space between the plate and spout 8 on sleeve 88 and causingjamming or binding of the plate. A plate 106 is secured to the main plate 90 and is transported therewith upon motion of the main plate. A vertical segment 108 of an actuator arm 110 is positioned within a groove 112 which is formed in the plate 106. An opposite end of the actuator arm is coupled to a rotary actuating member of a microswitch 114. As a bag is positioned on the spout 8, it engages the plate 90 and causes movement of the plate 90 in a direction substantially parallel to the axis of the spout. This causes the rod 110 to move rearwardly thereby actuating the microswitch. When a bag is blown from the spout during the fill mode or when it becomes improperly positioned during the fill mode, the plate 92 advances under the force of the springs in a direction parallel to the axis of the spout 8 and causes deactivation of the switch 114. The switch thus provides for sensing of the proper or improper positioning of a bag on the spout.

Referring once again to FIG. 5, this bag sensing switching represented by the rectangle 116 is coupled to a safety stop valve switching means 118 for generating a pneumatic signal which is applied to a pneumatic stop relay 120. The stop relay 120 generates a stop signal which is supplied to the fill cycle control valve 70 and causes switching of this valve, interruption of the fill cycle and transition to a dwell mode. The signal from the safety stop is also applied to the bag discharge control valve 82 which disables a gate 84 and inhibits operation of the bag discharge piston. In addition, the safety stop signal can be supplied by a malfunction from the bag applicator 39 for causing the packer to recycle to a dwell mode condition. In addition to generating a safety stop signal, the safety stop valving means 118 is adapted for enabling a gate valve 122 under normal operating conditions when the switching means 116 indicates the proper positioning of a bag on the spout 8. Thus, the switch means 116 is additionally advantageous in that it inhibits the initiation of an operating cycle until a bag is properly positioned on the spout 8.

The discharge of a partially filled bag from the spout is inhibited when the fill cycle is interrupted by the operation of a local manual stop button 124 by an operator of the apparatus, by the actuation of a remote manual stop button 126 by the actuation of the operator or by the generation of a safety stop signal as described hereinbefore. These signals are coupled to the stop relay 120 which causes the fill cycle control valve 70 to switch and to terminate the fill mode. In addition, these signals are also coupled to the bag discharge control valve 82. An output of the control valve 82 disables the gate 84 and inhibits the control of the bag clamp and discharge valve means 78 by the fill cycle control valve 70. The bag discharge piston and cylinder assembly 64 is therefore not energized as would normally be the case in a routine dwell mode. Thus, discharge of a partially filled bag, which can result for any of a number of reasons, and which has heretofore accompanied a termination of a fill cycle before routine completion will be inhibited by the described arrangement.

FIG. 6 illustrates the pneumatic control means of FIG. in greater detail. Those elements of FIG. 6 which perform similar functions as elements of FIG. 5 bear the same reference numerals. In particular, the

various valve switching means of FIG. 5 which are not represented by a single element in FIG. 6 are included within the dashed lines and the assembly of elements within the dashed lines bear the same reference numeral as the switching means in FIG. 5. The switching valve elements and 82 each comprise a four-way valve to which there is applied air pressure from a source represented as P. The pneumatic control signal inputs are applied to air bleed detector members 200. Switching of the valve is effected by establishing an air bleed at one of the detectors 200 of a valve. The valve then switches output lines to the valve segment adjacent to the bleed member which remains pressurized. For example, when the right hand bleed detector 200 of the valve 70 is vented by the scale stop switch 86 for example, the left hand lead detector 200 will remain pressurized and the valve outlet will switch from the right hand section as illustrated in FIG. 6 to its left hand condition. In the right hand condition illustrated, the line 204 is pressurized since it is coupled through the valve to its source of pressure P while the line 206 is vented since it is coupled through the valve to a vent port of the valve. As this valve switches to the left hand condition, the line 206 then becomes pressurized while the line 204 becomes vented. FIG. 6 illustrates the switch conditions of the various pneumatic elements during the fill mode of operation. Air lines which are pressurized in this mode are illustrated as solid lines while those air lines which are vented during this mode of operation are illustrated as dashed lines.

The bag clamp and discharge valve means 78 includes a four way time delay valve 208 and a four way sequence valve 210 as well as

flow control valves

212 and 214 which are positioned in the

air lines

216 and 218 respectively to the cylinder assembly 64. The time delay valve 208 is adapted to switch without a substantial delay when air pressure is applied to the air detector 220 while a time delay occurs in switching when air pressure is applied to the left hand air detector 222. The four way sequence valve 210 includes a spring biasing means 225 for resetting this valve to a predetermined condition. The feedgate valve means 76 comprises a four way time delay valve while the pressurizing and venting valve means 34 as well as the purge, clean out and expansion sleeve bleed valve means 74 each include a four way sequence valve with a spring offset. The safety stop valve means 118 includes a timed impulse relay 224 which is adapted for switching from a reset condition for a relatively short interval of time and thereby generating a short termed bleed impulse signal. The safety stop valve means 118 further includes a four way single solenoid operated and spring return valve 226. This valve is actuated by electrical energization of the solenoid through activation of the micro-switch 114. As indicated hereinbefore, the micro-switch 114 is activated when a bag engages the plate 90 at the spout 8.

In operation, a fill mode is manually initiated by actuation of the bleeder button valve 80. A bag will have been positioned on the fill s out either manually or during the execution of a previous dwell mode by the bag feed 39. The micro-switch 114 will then be actuated for applying electrical energy to the solenoid of the solenoid energized valve 226. This valve will have then switched to its right hand condition thereby coupling air pressure to the air detector of the gate valve 122. This gate valve is then enabled permitting the manual start button to vent the air detectors on the left hand side of the fill cycle control valve '70 and the bag discharge valve 82. These valves then switch to the line conditions as illustrated in FIG. 6. Air pressure is applied directly from the valve 70 to the cylinder piston assembly 28 and opens the valve 24 enabling the flow of material from the spout 8. The pressurized line 204 also causes switching of the four way time delay valve 208 of the bag clamp and discharge means 78. Pressure is then applied directly through the valve 208 and a line 230 to the bag clamp cylinder 52. A line 232 from the valve 208 is vented thereby resetting the valve 210. The pressurized line 204 also causes the feed gate valve 76 to switch resulting in the direct application of pressure through the valve 76 and an air line 234 to the cylinder and piston assembly 18 for closing the feed gate 12 and interrupting the flow of material from the upper hopper to the chamber 13.

Air pressure from the line 204 during this fill mode is also applied to a two way valve 236 and to a three way valve 238 for controlling the flow of a gas such as air to the spout 8 in order to establish a purge flow and to inflate the sleeve 88. The valve 236 is actuated for enabling the flow of pressurized gas through a flow control needle valve 240, through a line 242, and through a check valve 244. Bleeder gas which flows over the circuit to this valve inhibits compacting of material which could interfere and block the flow of material. The actuation of the three way valve 238 by air pres sure in the line 204 establishes a flow path from the gas pressure source P to the sleeve 88 via a gas pressure regulator 246, the valve 238 and a line 248.

The air line 206 from the valve 70 is vented during the fill mode and enables the pressurization of the storage chamber 13 with inert gas through valve 254. In addition, a four way sequence valve 252 actuates valve 256 and inhibits venting of the chamber 13. Line 206, which is pressurized in the dwell mode actuates valve 254 and interrupts the application of gas to chamber 13 and additionally causes the switching of valve 252 resulting in a momentary venting of the chamber through valve 256.

A single outlet air line 260 is coupled between the bag discharge control valve 82 and the gate valve 84 which comprises a three way relay valve. In the fill mode, the line 260 is vented and the valve 84 will remain in a reset condition thereby providing a flow path between the outlet line 206 of the valve 70 and an inlet of the valve 208. This enables the line 206, when subsequently pressurized during a dwell mode, to apply pressure to the valve 208 for initiating the discharge of a filled bag from the spout 8. However, when a fill mode is terminated before a bag is fully packed the valve 82 will be switched thereby pressurizing the line 260 and causing actuation of the valve 84 for disabling the cou pling of air pressure in the line 206 during the dwell mode to the valve 208. The discharge of a partly filled bag will thereby be inhibitedv During a fill mode, the valve 82 will be switched by actuation of the local and remote

manual stop valves

124 and 126 respectively. These valves comprise bleeder push button valves which are manually actuated by an operator. In addition, when a bag is blown from the spout during the fill cycle or is improperly positioned, the micro-switch 114 will become disengaged thereby deenergizing the solenoid of the valve 226 causing resetting of this valve. As valve 226 becomes reset, the left hand air detector of the valve 224 causes the valve to switch to the left hand condition resulting in a timed venting of an air line 262 and resetting of the valve 82 as indicated. Thus, the actuation of the switch 124, the switch 126 or an impulse from the valve 224 will disable the gate valve 84 and inhibit discharge of a partially filled bag.

During normal operation, the bag will contain a predetermined weight at which time, the bag chair weight sensing means 62 (FIG. 1) will cause actuation of a scale stop bleeder button valve 86 and vent the right hand air detector 200 of the valve 70. The valve thereby switches to its left hand condition whereby the line 204 becomes vented while the line 206 becomes pressurized. Under these conditions, a pressure is applied to the cylinder and piston assembly 28 causing the valve 24 to close and disable the further flow of mate rial from the spout 8. The pressure in line 206 is applied via the gate valve 84 to the valve 208 causing delayed switching thereof and the pressurization of the line 232. Pressure from the line is applied to the bag clamping cylinder 52 and causes retraction of the piston 51. In addition. the pressure in line 232 is applied to the valve 210 which causes momentary switching thereof and actuation of the bag discharge piston for causing discharge of the bag from the spout 8. The pressurized line 206 during this dwell mode further causes delayed switching of the feed gate valve 76 thereby pressurizing line 266. This pressurizes the cylinder assembly 18 and causes the valve 12 to open thereby permitting flow of material from the upper hopper 10 to the chamber 13. During this dwell mode, the line 206 also applies pressure to the valve 254 for interrupting the application of inert gas pressure to the chamber 13 while simultaneously causing switching of the valve 252. This valve switches and momentarily enables the valve 256 thereby venting the chamber 13. After a short delay, the valve 252 returns to its reset condition and interrupts the venting of the chamber 13.

At the termination of a fill cycle, it is desirable to flow gas such as air under substantial pressure to the fill spout 8 in order to inhibit packing and blockage of passages within the spout. To this end, the pressure in line 206 is also applied to the valve 250 which is switched momentarily thereby energizing the valve 253 and allowing pressure from the source P to flow over an unrestricted path through the valve 253, and the line 242 to the spout. Thus, a gas such as air under relatively high pressure is applied to the spout for a short interval of time. After a short delay, the valve 250 automatically resets thereby disabling the valve 253 and interrupting the flow of gas from the source P to the spout.

During the dwell mode of operation, the line 204 which is vented permits resetting of the valve 236 and the valve 238. The valve 236 then interrupts the flow of purging gas to the spout while resetting of the valve 238 interrupts the flow of gas to the expansion sleeve described which advantageously provides for the disabling of the flow of material to a bag when a fill mode of operation of the apparatus has been interrupted before routine completion ofthe fill mode. The dispersion of the material in the air about the apparatus is thus reduced and the efficiency of operation is enhanced while the operator discomfort and potential for dust explosions is substantially reduced.

While I have described a particular embodiment of my invention, it will be apparent to those skilled in the art that various modifications may be made thereto without departing from the spirit of the invention and the scope of the appended claims.

What is claimed is:

l. A bag packing apparatus having an operating cycle including a fill mode and a dwell mode comprising:

storage means for receiving and containing a powdered or finely granulated material which is to be packed into a bag;

an elongated spout communicating with said storage means;

means for conveying material from said storage means to said spout and for causing the material to flow from said spout;

a first material flow control means for cyclically enabling the discharge of material from said spout into a bag positioned on said spout during a fill mode interval of said operating cycle and for disabling the flow of material from said spout during a dwell mode interval of said operating cycle; wherein said' first material flow control means includes a value means for enabling or disabling the flow of material from said spout. actuating means for activating said valve between flow enabling and flow disabling positions, a pneumatic bistable fill cycle control valve having first and second outlet lines, and means coupled to said fill cycle control valve and said actuating means for causing the activation of said material flow control valve to a closed position when said fill cycle valve is in a first state and to an open position when said fill cycle valve is in a second state;

means for supplying and positioning an empty bag about said spout and for discharging a filled bag from said spout during a dwell mode interval of said operating cycle; and

a second material flow control means including a switch, said switch positioned at said spout for engagement by a bag when a bag is positioned on the spout, said second material control means arranged for disabling the flow of material during a fill mode interval of said operating cycle when a bag on said spout becomes disengaged from said switch wherein said second flow control means includes a pneumatic signalling element coupled to said fill cycle control valve and responsive to said switch for causing said fill cycle control valve to switch from said second to said first condition when a bag becomes disengaged from said switch.

2. The bag packing apparatus of claim 1 wherein said storage means comprises a chamber and said means for conveying material from said storage means to said spout comprises a source of gas and means for conveying said gas to said chamber for fluidizing said material.

3. The bagging apparatus of claim 2 including an electrical switch positioned near said fill spout, an actuating plate extending in a direction which is generally normal to the length of said spout, meansfor supporting and biasing said plate on said spout in a forward position for engagement by a bag which'is positioned on said spout, and means coupled between said plate and said switch for actuating said switch when a bag engages said plate and causes rearward motion of said plate.

4. The apparatus of claim 3 wherein said means for supporting said biasing said plate comprise first and second rods, support means having apertures formed therein and through which said rods are adapted to extend. and coil spring means positioned about said rods and adapted for compression against said support means when a bag engages said plate and causes rearward motion of said plate.

5. The bagging apparatus of claim 1 including an electrical switch positioned near said fill spout, an actuating plate extending in a direction which is generally normal to the length of said spout, means for supporting and biasing said plate on said spout in a forward position for engagement by a bag which is positioned on said spout, and means coupled between said plate and said switch for actuating said switch when a bag engages said plate and causes rearward motion of said plate.

6. The apparatus of claim 5 wherein said means for supporting and biasing said plate comprise first and second rods, support means having apertures formed therein and through which said rods are adapted to extend, and coil spring means positioned about said rods and adapted for compression against said support means when a bag engages said plate and causes rearward motion of said plate.

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Claims

1. A bag packing apparatus having an operating cycle including a fill mode and a dwell mode comprising: storage means for receiving and containing a powdered or finely granulated material which is to be packed into a bag; an elongated spout communicating with said storage means; means for conveying material from said storage means to said spout and for causing the material to flow from said spout; a first material flow control means for cyclically enabling the discharge of material from said spout into a bag positioned on said spout during a fill mode interval of said operating cycle and for disabling the flow of material from said spout during a dwell mode interval of said operating cycle; of said operating cycle wherein said first material flow control means includes a value means for enabling or disabling the flow of material from said spout, actuating means for activating said valve between flow enabling and flow disabling positions, a pneumatic bistable fill cycle control valve having first and second outlet lines, and means coupled to said fill cycle control valve and said actuating means for causing the activation of said material flow control valve to a closed position when said fill cycle valve is in a first state and to an open position when said fill cycle valve is in a second state; means for supplying and positioning an empty bag about said spout and for discharging a filled bag from said spout during a dwell mode interval of said operating cycle; and a second material flow control means including a switch, said switch positioned at said spout for engagement by a bag when a bag is positioned on the spout, said second material control means arranged for disabling the flow of material during a fill mode interval of said operating cycle when a bag on said spout becomes disengaged from said switch wherein said second flow control means includes a pneumatic signalling element coupled to said fill cycle control valve and responsive to said switch for causing said fill cycle control valve to switch from said second to said first condition when a bag becomes disengaged from said switch.

3. The Bagging apparatus of claim 2 including an electrical switch positioned near said fill spout, an actuating plate extending in a direction which is generally normal to the length of said spout, means for supporting and biasing said plate on said spout in a forward position for engagement by a bag which is positioned on said spout, and means coupled between said plate and said switch for actuating said switch when a bag engages said plate and causes rearward motion of said plate.

4. The apparatus of claim 3 wherein said means for supporting said biasing said plate comprise first and second rods, support means having apertures formed therein and through which said rods are adapted to extend, and coil spring means positioned about said rods and adapted for compression against said support means when a bag engages said plate and causes rearward motion of said plate.