US2968948A - Sampling device for bag filling apparatus - Google Patents

Description

Jan. 24, 1961 B. w. ROSE 2,963,943

SAMPLING DEVICE FOR BAG FILLING APPARATUS Filed May 18, 1956 2 Sheets-Sheet '1 E'IE 1 I04 IOI INVENTOR BOYD W. ROSE ATTORNEY Jan. 24, 1961 B. w. ROSE 2,968,948

SAMPLING DEVICE FOR BAG FILLING APPARATUS Filed May 18, 1956 2 Sheets-Sheet 2 N m r. q gm l0 IDLQI 8 mm W 53 row 0') Q m Q m m K) n- 0 t m 1 5 Q p. s U m m m P r 2 Q (\S Q [\J a:

b I m (\S 1' 3 U) m m H INVENTOR \O BOYD w. ROSE ATTORNEY United States Patent Ofiice Patented Jan. 24, 1961 SAMPLING DEVICE FOR BAG FLLLING APPARATUS Boyd W. Rose, Riverside, Calif., assignor to Food Machinery and Chemical Corporation, San Jose, Calif., a corporation of Delaware Filed May 18, 1956, Ser. No.-585,809

8 Claims. (Cl. 73-421) This invention relates generally to machine for filling bags with fluidized powdered or granular material. More particularly the invention is directed to a sampling mechanism for such a machine.

In a prior patent of Paul C. Aust, No. 2,795,389, issued June 11, 1957, and entitled Apparatus for Filling Powdered Materials into Containers, and in my prior Patent No. 2,866,484, entitled Apparatus for Filling Bags, issued December 30, 1958, is disclosed a bag filling machine of the type referred to herein, and the present invention constitutes an improvement of the machine disclosed in said applications.

In the filling of bags with powdered material, it is often desirable, and under some contract conditions mandatory, to obtain samples of the material actually being deposited in the bags. It is therefore an object of this invention to provide a mechanism, for use with a bag filling machine of the type shown in the above mentioned applications, to enable the taking of a sample of the material actually being deposited in the bags simultaneously with the bag filling operation.

Various other objects of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a schematic view of a bag filling machine embodying the principles of the invention and illustrating the pneumatic control systems used in the machine.

Fig. 2 is an elevation partly in section of a portion of the bag filling machine and illustrates the specific structure of the sampling device of the instant invention.

Fig. 3 is an elevation of the sampling mechanism taken generally on line 3--3 of Fig. 2 looking in the direction of the arrows.

My above mentioned Patent No. 2,866,484 discloses an improved nozzle structure and an improved cut-off device for controlling the flow of the fluidized material through the nozzle. The instant invention is disclosed in connection with such an improved apparatus and reference is made to said patent for the specific details thereof.

In the bag filling mechanism a bag B (Fig. 1) is placed in a :bag support unit 11 which is, in turn, mounted on a scale 12. The bag B is of the type wherein the material enters the bag through a generally tubular portion V that is known as a bag valve. In order to fill the bag B, the valve V thereof is positioned in place about a filling spout 13 which is in communication with a supply tank 14 and the bag is clamped in this position by movement of .the spot against a static-nary clamping structure 15. The fluidized material is thereafter directed from the supply tank 14 into the bag B through the filling spout 13. As the bag B is being filled, the bag and its contents are continuously weighed by the scale 12. When a desired weight of material has been deposited in the bag, the scale automatically activates the pneumatic control system to actuate a double acting power cylinder .16 to close a valve assembly 17 and stop the flow of material through the spout 13. The sampling mechanism of the instant invention comprises a spout 18 located at the rear of the supply tank 14 and having a valve mechanism 19 actuated by a power cylinder 26 connected to the exhaust of the power cylinder 16 when said cylinder is moved to its position cutting off the flow through the main spout 13.

As set forth in the above mentioned Aust Patent, the tank 14 is provided with a plenum chamber 21 extending completely across the bottom thereof and separated from the remainder of the tank by a pourous canvas membrane 22. A conduit 23 connects the plenum chamber 21 with a source of air under pressure in the manner ex plained below.

The main spout 13 (Figs. 1 and 2) is pivotally mounted at 24 for movement toward and away from the bag holding member 15 by a power cylinder 25 the piston 26 of which is connected to a crank arm 27 fixed to the pivot pin 24. A rubber sleeve 23 surrounds the spout 13 and is adapted to be inflated by air supplied through a conduit 29 to completely fill the bag valve opening V and prevent blow-by of the material being deposited in the bag B. A rubber tube 34) connects the spout 13 with the supply tank 14 and is adapted to be pinched by the valve mechanism 17 under the influence of the power cylinder 16 in the manner disclosed in my above identified patent to cut off the flow of material therethrough.

The sampling tube or spout 18 is of relatively smaller diameter than the main spout 13 and is made of rubber or similar flexible and resilient material. The spout 18 is clamped, as indicated at 31, to the inner surface of the supply tank 14 and projects outwardly and downwardly therethrough in the manner illustrated in Fig. 2. A plate 32, having a suitable opening for the spout 18 to project through, is fixed to the rear surface of the supply tank 14 by a pair of bolts 33. A cylindrical member 34 is welded or otherwise fixed to the plate 32 adjacent the lower surface of the spout 18. A bracket 35 is fixed to the plate 32 and extends diagonally upwardly and outwardly therefrom substantially perpendicularly to the axis of the spout 18. The power cylinder 20 previously mentioned is fixed to the upper portion of the bracket 35. A guide block 36 is fixed to the bracket 35 by a pair of cap screws indicated at 37. The guide block 36 is provided with two bores 38 and 39 adapted to slidably receive the legs 40 and 41 of a U-shaped stirrup member generally indicated at 42. The lower cross member 43 of the stirrup 42 is in contact with the upper surface of the tube 18 and is adapted to pinch the tube 18 against the member 34. A cylindrical plate 44- is fixed to the upper surface of the cross member 43 and a cylindrical spring guide pin 45 extends upwardly therefrom. A compression spring 46 surrounds the guide pin 45. One end of the spring 46 abuts the plate 44 and the other end is received within a suitable blind bore 47 in the undersurface of the guide block 36, where-by the spring 46 urges the stirrup member 42 to its tube pinching position, illustrated in Figs. 2 and 3, to cut off the flow of material through the sample tube 18.

The stirrup member 42 is connected to the power cylinder 20 for movement thereby in the following manner. A crosshead 50 is adjustably secured to the upper ends of the legs 40 and 41 of the stirrup member 42 by a plurality of nuts 51 threadedly received on the legs 40 and 41 one above and one beneath the crosshead 50 on each of said legs. The underside of the central portion of the crosshead 50 is provided with a blind bore 52 adapted to receive the upper end of a piston rod 53 which is held therein by a set screw 54. The piston rod 53 extends downwardly through the upper end of the power cylinder 20 and is connected at its lower end to the piston 55 therewithin. A second compression spring 56 surrounds the piston rod 53 and is confined between the upper end of the cylinder 20 and the piston 55. A port 57 in the cylinder 28 is adapted to permit the introduction of pressure fluid beneath the piston 55.

From the foregoing description it may be seen that the stirrup 42 is normally urged downwardly by the springs 46 and 56 to pinch the tube 18 against the member 34 and prevent any flow through the tube 18 but is adapted to be raised by the introduction of pressure fluid, in a manner to be described, through the port 57 to permit the flow of material through said tube 18.

The pneumatic control circuits for the device are similar to those disclosed in my above identified patent and are illustrated schematically in Fig. 1. Air under pressure from a suitable source (not shown) enters the system through a conduit 60 and a filter 61. After the air passes through the filter 61 it branches into three distinct systems by means of conduits 62, 63 and 64. The air from conduit 62 passes through a suitable pressure regulating valve 65 into conduit 23 and hence into the plenum chamber 21.

Air from the second branch conduit 63 passes through a pressure regulator 66 to a conduit 67 connected to a three way valve 68. The valve 68 comprises a tubular housing 69 having a valve spool 70 slidably mounted therein. A spring 71 normally urges the spool 70 upwardly to a position wherein the lower end of the spool covers a port 72 in the housing and at the same time provides communication between the conduit 67 and the conduit 29 connected to the inflatable member 28 on the spout 13 to inflate the same and seal the opening between the spout 13 and the bag opening V. The spool 70 is adapted to be urged downwardly by air pressure applied to its upper end through a conduit 73 in a manner hereinbelow described to close the inner end of the conduit 67 and connect the conduit 29 with the discharge port 72 thus permitting the seal member 28 to deflate and release the bag B.

The air from the conduit 64 passes through a pressure regulator 75 and a conduit 76 to a lubricator 77. A conduit 78 carries the air from the lubricator 77 to a master valve 79.

The master valve 79 (Fig. 1) comprises a housing 80 having a cylindrical chamber 81 and a distribution chamber 82. A spool 83, having an annular groove 84 around its midpoint, is slidably mounted within the cylindrical chamber 81 of the housing 80. A small air passageway 85 is provided in the surface of the spool 83 extending longitudinally thereof to allow air to flow to each end of the cylindrical chamber 81 of the housing 80. High pressure air from the conduit 78 enters the master valve 79 through an inlet port 86 and then flows to each end of the cylindrical chamber 81 as previously mentioned. From the chamber 81 air flows through a slot 87 provided in an inner wall 88 of the housing 80 and into the distribution chamber 82. A slide valve 89 is slidably mounted Within the distribution chamber 82 and is connected to the spool 83 by means of an arm 90', which extends through the slot 87 and is received within the annular groove 8 of the spool 83 for movement therewith. In order to be assured of a supply of air at each end of the cylindrical chamber 81, the spool 83 is prevented from contacting the ends of the chamber 81 due to the fact that the arm 90 contacts the end walls of the slot 87 before the spool reaches the end of the chamber 81. The slide valve 89 is provided with two internal chambers 91 and 92 which are sealed from the high pressure air within the distribution chamber 82. In order to provide flow passages between adjacent ports in the chamber 82, the chambers 91 and 92 are arranged to overlap different ports provided in the housing 80. When the master valve 79 is positioned as shown in Fig. 1, a port 93 is in direct communication by means of the chamber 92 with a port 94; a third port 95 is in communication with the chamber 91; and a port 96 is in communication with the distribution chamber 82 and the high pressure air contained therein. When the spool 83 and the attached slide valve 89 are moved to the left (Fig. 1), the port 93 is opened to the high pressure air contained within the distribution chamber 82, and the port 96 is in communication with the port through the chamber 91.

The master valve 79 is of the type in which a temporary unbalance of the air pressure on the ends of the spool 83 will cause the spool and attached slide valve 89 to shift position in the housing. This unbalanced condition is achieved by momentarily opening normally closed spring loaded air bleeder valves disposed in air conduits which communicate with each end of the cylindrical chamber 81. When one of the valves is held in an open position for a short time, a small amount of air will bleed from one side of the cylindrical chamber 81 causing the above-mentioned unbalanced air pressure and thereby causing the spool 83 to be shifted to the low pressure end.

The above-mentioned valves comprise a manually operated start valve 100, a manually operated stop valve 101 and a scale actuated stop valve 102. The start valve 100 is conveniently positioned at the front of the machine adjacent the operators position and is in communication with the right end of the chamber 81 of the master valve 79 through a conduit 183. Similarly, the stop valve 101 is positioned at the front of the machine adjacent the operators position and is in communication with the left end of the cylindrical chamber 81 of the master valve 79 through a conduit 104. The scale actuated stop valve 102 is mounted on the frame of the machine adjacent the scale 12 and is adapted to be actuated thereby when the scale 12 is pivoted counterclockwise by the weight of a bag which has received a desired quantity of material. The scale actuated valve 102 is connected in parallel with the stop valve 101 by the conduit 105.

Thus, when the start valve 100 is momentarily actuated, the spool 83 and attached slide valve 89 are forced to slide to the right into the position shown in Fig. 1 allowing air to flow through the port 93, through the chamber 92 and out the port 94, and also allowing high pressure air contained in the distribution chamber 82 to flow out the port 96. When either the stop valve 101 or the scale actuated valve 102 is momentarily actuated, the spool 83 and the attached slide valve 89 slide to the left thereby opening the port 93 to high pressure air contained within the distribution chamber and allowing air to flow from the port 96, through the chamber 91 and out the port 95. A conduit connects the discharge port 95 of the valve 79 with the port 57 of the power cylinder 20 of the sample taking device. A branch conduit 111 connects the conduit 110 to an adjustable needle valve 112 which in turn is vented to the atmosphere.

The port 96 of the master valve 79 is connected by a conduit 116 to the double acting power cylinder 16 at a point located below the piston therein. Another conduit 117 connects the port 93 and the power cylinder 16 at a point above the piston. Thus, with the spool 83 of the master valve 79 positioned at the right hand end of the chamber 81 as shown in Fig. 1, high pressure air flows through the conduit 116, raises the piston in the power cylinder 16 and opens the valve mechanism 17. At the same time, the air in the upper portion of the power cylinder is vented through the conduit 117, the chamber 92, and the port 94. When the spool of the master valve 79 is positioned at the left hand end of the chamber 81, high pressure air flows through the conduit 117 to the top of the power cylinder 16 to force the piston therein downwardly to close the valve mechanism 17. In this case, the lower portion of the power cylinder is vented through the conduit 116. the chamber 91, the port 95, and the conduit 110 to actuate the power cylinder 20 to open the valve mechanism 19 and the spout 18.

The pressure gradually bleeds from the line 110 through the needle valve 112 and the valve mechanism 19 closes under the influence of springs 46 and 56 to again clamp the spout 18.

A conduit 120 is connected to the conduit 116 to allow air to flow to a needle valve 121 and to a by-pass check valve 122 which are connected in parallel. The by-pass check valve 122 allows air to rapidly flow to the left as viewed in Fig. 1 but prevents air from flowing in the opposite direction. A conduit 123 communicates the needle valve 121 and by-pass check valve 122 with the bag clamping cylinder 25. Thus, when the master valve 79 is positioned as shown in Fig. 1, air rapidly flows from the conduit 116, through the needle valve 121 and by-pass check valve 122, through the conduit 123, and into the bag clamping cylinder 25 to thereby rapidly pivot the filling spout 13 into a bag clamping position. Upon shifting the spool 83 of the master valve 79 to the left (Fig. 1), air is allowed to slowly escape from the bag clamping cylinder 25, through the conduit 123, and the needle valve 121 and into the valve chamber 91 where it is vented to the atmosphere through the port 95, the conduit 110 and the needle valve 112. Thus, with the above arrangement, the filling spout 13 is rapidly pivoted to the bag clamping position but is slowly pivoted away from the bag clamping position into the bag releasing position.

As previously mentioned, the spool 70 of the three-way valve 68 is urged to its upper position in the housing 69 by a spring 71 and is moved to its lower position by high pressure air entering through conduit 73. In order to control the position of the spool 70 within the three-way valve 68, the aforementioned conduit 117, which is connected to the port 93 of the master valve 79, is connected by a branch conduit 125 to a needle valve 126 and a bypass check valve 127. Air may flow through the bypass check valve 127 to the left as shown in Fig. 1 but is prevented from flowing in the opposite direction. The needle valve 126 and by-pass check valve 127 are connected to the previously described three-way valve 68 by the conduit 73. When the spool 83 of the master valve 79 is positioned at the right as shown in Fig. 1, air in the conduit 117 is vented through the chamber 92 and the port 94. This allows the spool 70 of the threeway valve 68 to rapidly move upwardly to the position shown in Fig. l to open the conduit 29 leading to the bag 'seal to inflate the seal with low pressure air. Upon actuating the master valve 79 so that the spool 83 is positioned to the left (Fig. 1), air will flow from the master valve 79 through the port 93, slowly through the needle valve 126, through the conduit 73 and into the three-way valve 68 to thereby slowly move the spool 70 downwardly to shut off the supply of low pressure air to the bag seal 28 and to allow the air contained in the seal to escape to the atmosphere through the port 72 previously described.

From the foregoing description it may be seen that when the needle valve 112 is fully open the valve mechanism 19 is inoperative because no pressure ever builds up in the conduit 110. However, when it is desired to take samples, it is merely necessary to partially close the needle valve 112 to permit temporary build-up of pressure in the conduit 110 each time the main valve 17 closes. The length of time that the sample valve 19 remains open and hence the size of the sample taken may be accurately controlled by proper adjustment of the needle valve 112.

While a preferred embodiment of the invention has been shown and described herein, it is obvious that various changes may be made therein without departing from the spirit of the invention as defined in the appended claims.

Having thus disclosed the invention, what I claim and desire to secure by Letters Patent is:

1. A sampling mechanism for use with a bag filling machine having a supply tank, a main filling spout, a

valve for controlling the flow through said main filling spout, and a first power cylinder for actuating said valve, a discharge conduit connected to said first power cylinder, said sampling mechanism comprising a sampling spout extending outwardly and downwardly from said supply tank, a valve mechanism for controlling the flow through said sampling spout, spring means normally urging said valve mechanism toward its closed position, a second power cylinder connected to said valve mechanism for moving said mechanism toward its open position, conduit means connecting said second power cylinder with the discharge conduit of said first power cylinder, and a needle valve in said conduit means vented to the atmosphere to slowly bleed the pressure from said conduit means and permit said valve mechanism to be closed by said spring means.

2. A sampling mechanism for use with a bag filling mach-inc having a supply tank, a main filling spout, a valve for controlling the flow through said main filling spout, and a double acting power cylinder for actuating said valve, discharge conduits connected to the opposite ends of said double acting power cylinder, said sampling mechanism comprising a sampling spout extending outwardly and downwardly from said supply tank, a valve mechanism for controlling the flow through said sampling spout, spring means normally urging said valve mechanism toward its closed position, a second power cylinder connected to said valve mechanism for moving said mechanism toward its open position, conduit means connecting said second power cylinder with the discharge con duit at one end of said double acting power cylinder, and a needle valve in said conduit means vented to the atmosphere to slowly bleed the pressure from said conduit means and permit said valve mechanism to be closed by said spring means.

3. A sampling mechanism for use with a bag filling machine having a supply tank, a main filling spout, a valve for controlling the flow through said main filling spout, and a double acting power cylinder for actuating said valve, discharge conduits connected to the opposite ends of said double acting power cylinder, said sampling mechanism comprising a sampling spout extending outwardly and downwardly from said supply tank, a valve mechanism for controlling the flow through said sampling tube, spring means normally urging said valve mechanism toward its closed position, a second power cylinder connected to said valve mechanism for moving said mechanism toward its open position, conduit means connecting said second power cylinder with the discharge conduit at the end of said double acting power cylinder through which fluid is discharged when said valve is moved to its closed position, and a needle valve in said conduit means vented to the atmosphere to slowly bleed the pressure from said conduit means and perm-it said valve mechanism to be closed by said spring means.

4. A sampling mechanism for use with a bag filling machine having a supply tank, a main filling spout, a valve for controlling the flow through said main filling spout, and a first power cylinder for actuating said valve, a discharge conduit connected to said first power cylinder, said sampling mechanism comprising a resilient sampling spout extending outwardly and downwardly from said supply tank, a stirrup member mounted adjacent said sampling spout and adapted to pinch said spout for controllin the flow through said sampling spout, spring means normally urging said stirrup member toward its spout pinching position, a second power cylinder fixed to said tank and connected to said stirrup member for moving said stirrup member away from said spout, conduit means connecting said second power cylinder with the discharge conduit of said first power cylinder, and a needle valve in said conduit means and vented to the atmosphere to slowly bleed the pressure from said conduit means and permit said stirrup member to be moved by said spring means to its spout pinching position.

5. A sampling mechanism for use with a bag filling machine having a supply tank, a main filling spout, a valve for controlling the flow through said main filling spout, and a first power cylinder for actuating said valve, 3. master valve for controlling the actuation of said first power cylinder, a conduit connecting said first power cylinder to said master valve, said sampling mechanism comprising a sampling spout extending outwardly and downwardly from said supply tank, a valve mechanism for controlling the flow through said sampling spout, spring means normally urging said valve mechanism toward its closed position, a second power cylinder connected to said valve mechanism for moving said mechanism toward its open position, conduit means connecting said second power cylinder with a discharge port of said master valve, and a needle valve in said conduit means vented to the atmosphere to slowly bleed the pressure from said conduit means and permit said valve mechanism to be closed by said spring means.

6. A sampling mechanism for use with a bag filling machine having a supply chamber, -a main filling spout connected to said supply chamber, and a pressurized fluid actuated valve for controlling the flow through said main filling spout, said sampling mechanism comprising a sampling tube connected to said supply chamber, a valve mechanism for controlling the flow through said sampling tube, and pressurized fluid actuated means responsive to the closing of said pressurized fluid actuated valve and operatively connected to said sampling tube valve mechanism for moving said valve mechanism toward its open position.

7. A sampling mechanism for use with a bag filling machine having a supply chamber, a main filling spout connected to said supply chamber, and a fluid actuated valve for controlling the flow through said main filling spout, said sampling mechanism comprising a sampling tube connected to said supply chamber, a valve mecha-' nism for controlling the flow through said sampling tube, fluid actuated means for moving said valve mechanism toward its open position, means responsive to the closing of said fluid actuated valve and connected to said fluid actuated means to open said valve mechanism, and means operatively connected to said last mentioned means to release said fluid actuated means and permit said valve mechanism to close after a predetermined time interval.

8. In a bag filling machine having a material supply tank, a bag filling spout communicating with the supply tank, a valve arranged to close the filling spout, and a first power cylinder arranged to move said valve to spout closing position when actuated, the improvement comprising a sampling spout communicating with the supply tank, normally closed valve means connected to said sampling spout and movable to an open position opening the sampling spout, a second fluid actuated power cylinder connected to said sampling spout valve means and arranged to move said valve means to open position upon being actuated, means connecting said power cylinders for simultaneous actuation to close said filling spout and open said sampling spout to permit material to be taken from the supply tank through said sampling spout upon closing of the filling spout valve, and fluid control means communicating with said second power cylinder to control the time of closing of said sampling spout valve means whereby a material sample of predetermined quantity is taken from the supply tank.

References Cited in the file of this patent UNITED STATES PATENTS

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