Patent Publication Number: US-3875980-A

Title: Extinguisher charging system

Description:
United States Patent 1 Getz [ Apr. 8, 1975 EXTlNGUlSl-[ER CHARGING SYSTEM [76] Inventor: Melvin R. Getz, 1 10 Mt. Aire Dr.,  
 East Peoria, 111. 61611 221 Filed: May 14,1973  
 [211 App]. No; 359,928  
 [52] US. Cl. 141/83; 141/104; 141/286; 141/31 1 [51] Int. Cl B65b 3/28 [58] Field of Search l4l/59, 286, 311, 392, 141/83, 206,100,104,102,101,103,109, 106, 107  
 [56] References Cited UNITED STATES PATENTS 1,149,844 8/1915 Lieber 141/286 1,325,991 12/1919 King 141/59 2.755.968 7/1956 Fiant 141/311 3,078,685 2/1963 Flournoy 141/59 3.780.757 12/1973 Jordan 141/59 FOREIGN PATENTS OR APPLICATIONS 889,564 9/1953 Germany 141/59 Primary Examiner-HoustonS. Bell, Jr.  
 [57] ABSTRACT A system for vacuum-filling fire extinguishers with a measured charge of discrete fire-retardant material. The system includes a vacuum source and vacuum control means, and one or more reservoirs of fire retardant material. A vacuum and filling conduit means selectively connect the vacuum control means and each reservoir with the extinguisher to be filled, and coupling and sealing means joins said conduit means to the extinguisher in a sealed relationship. Filtering means are also provided to filter the fire-retardant material from the vacuum system.  
 9 Claims, 4 Drawing Figures EXTINGUISHER CHARGING SYSTEM BACKGROUND AND GENERAL DESCRIPTIGN This invention relates to a system for vacuum-filling fire extinguishers with powdered fire-retardant materials.  
  As wellknown in the fire-prevention field, standard cylindrical fire extinguishers must be recharged periodically with fresh fire-retardant materials, to maintain the extinguishers in an operative condition. Recharging obviously is also necessary after each extensive use of the extinguisher. Due to these requirements, a substantial industry has developed for providing fire extinguisher users with extinguisher recharging service.  
  The extinguisher recharging techniques that have been standard in the industry are generally slow, cumbersome and inefficient, and result in substantial labor costs. Generally, the standard recharging is to fill a host of various-sized extinguishers with the desired fireretardant powder manually through the open orifice provided at the top of the extinguisher. Scoops and funnels are usually employed in an effort to minimize spillage of the powder and speed-up the charging process. These prior techniques have met with only partial success.  
  Accordingly, the principal purpose of this invention is to provide an improved vacuum-filling system for recharging fire extinguishers which substantially minimizes the labor and time needed to fill a variety of different-sized extinguishers with a selected type of fireretardant powder. The system in accordance with this invention also substantially reduces the loss of materials during the recharging operation, by providing a closed system for controlling the material flow.  
  Briefly described, the system in accordance with this invention utilizes a partial vacuum force to fill empty fire extinguisher cylinders with a measured charge of discrete fire retardant material. The system includes a station for receiving an empty and open extinguisher to be recharged. In the preferred arrangement, the station includes a scale for measuring the weight of the material introduced into the extinguisher. A vacuum system including a source of vacuum and a control valve between an opened and a closed position is also provided. One or more reservoirs is included to store the material to be charged into the extinguishers. Vacuum and filling conduit means having movable ends are joined to the vacuum control valve and reservoir respectively. Coupling and sealing means are provided to join the movable ends of the conduit means in sealed relationship to the different-sized orifices of a plurality of extinguishers. Filter means are also provided to filter and collect the material to avoid contamination of the vacuum system. In accordance with this invention the system is arranged so that selective movement of the control valve from a closed to an open position with the conduits secured within a fire extinguisher, draws a partial vacuum within the extinguisher through the vacuum conduit and thereby creates a pressure differential which rapidly draws the fire-retardant material from the reservoir into the extinguisher. In the preferred arrangement the system is provided with a plurality of vacuum and filling conduits which are adapted to feed a plurality of different fire-retardant materials selectively into the fire extinguisher being charged.  
  Further objects and features of the present invention will become more apparent from the following description of an embodiment thereof, taken in conjunction with the accompanying drawings, in which:  
  FIG. 1 is a plan view of the system for vacuum-filling fire extinguishers in accordance with this invention;  
  FIG. 2 is an enlarged partial sectional view of the interface between the vacuum-filling system and a fire extinguisher to be filled;  
  FIG. 3 is a cross-sectional view of the coupling and sealing means included in the system, as viewed along the line 33 in FIG. 2; and  
  FIG. 4 is an end view of thematerial reservoirs included in the filling system, illustrating the manner in which the reservoirs are filled;  
  The vacuum filling system in accordance with this invention is generally indicated in the drawings by the reference numeral 10. The system 10 is designed to rapidly charge empty fire extinguishers, such as an extinguisher 100, by creating a partial vacuum force within the extinguisher which causes firesuppressant powder to be drawn rapidly into the evacuated extinguisher within a matter of seconds. Moreover, the system 10 can be used with a variety of extinguishers 100, which include inlet orifices 102 of varying diameters. In addition, the preferred embodiment ofthe filling system 10 in accordance with this invention is adapted to selectively fill the fire extinguisher with any one of a plurality of fire retardant powders, such as the standard BC powder, Purple K powder, or ABC powder, in one simple and quick operation.  
  As seen in FIG. 1, the system 10 includes an extinguisher filling station 20. Station 20 includes a suitable stand 22 and an extinguisher weighing scale 24. The extinguishers 100 to be filled are placed on the scale 24 at the station 20 during the filling operation. The scale 24 registers the empty weight of the extinguisher 100, and is utilized during the filling operation to measure the amount of powdered fire-suppressant material being charged into the empty extinguisher. The scale 24 therefore provides a ready measurement, by weight, of the amount of material charged into the extinguisher 100, and provides indicia which informs the operator of the system 10 when the extinguisher 100 has been completely filled.  
  The system 10 further includes a vacuum system 30 for creating a partial vacuum within the extinguisher 100, to initiate the extinguisher filling operation. As seen in FIG. 1, the vacuum system 30 includes the vaccum pump 32 mounted on top of a vacuum storage tank 34. A suction line 36, including an air filter 38, connects the storage tank 34 to the inlet side of the pump 32. Similarly, an exhaust line 40 connects the outlet side of the pump 32 to the atmosphere through an air filter and muffier 44. The pump 32 is operated automatically through a suitable electrical power source (not shown) by means of a vacuum switch 46.  
 The vacuum switch 46 is of standard construction, and  
 is placed in the suction line 36 between the tank 34 and the pump 32. The switch 46 is adapted to energize the pump 32 periodically, to maintain a selective level of vacuum pressure within the vacuum storage tank 34. In the preferred embodiment, the switch 46 is set to energize the pump 32 when the vacuum level within the storage tank 34 falls to 14 inches of water vacuum pressure, and to de-energize the pump 32 after the tank 34 has been restored to 20 inches of water vacuum pressure. A one-way check valve 42 of standard construction is provided in the suction line 36 between the vaccum switch 46 and the pump 32 to maintain the vacuum pressure within the tank 34. Thus, the vacuum system 30 provides the filling system with a constantlyavailable source of vacuum pressure within the 14 to inch vacuum pressure range.  
  The vacuum system also includes a manual vacuum control console 50. As seen in FIG. 1, the control console 50 incorporates a plurality of vacuum control valves 52 AC. The valves 52 AC are manually movable between a closed position (as shown by valves 52 B and C) and an opened position (as shown by the valve 52 A) to initiate the operation of the filling system 10. A vacuum line 54 connects the inlet side of the valves 52 AC to the vacuum storage tank 34. A vacuum gauge 56 is provided in the line 54 to provide the operator with a readily available indication of the level of vacuum pressure existing in the vacuum system 30. An air filter 58 is provided in. the line 54 for filtering out small particles of the powdered fire-suppressant material which may enter the vacuum system, during the filling operation, to avoid contamination of the vacuum storage tank 34 and damage to the vacuum pump 32. It has been found that a suitable filter 58 is a combination cloth and paper tank-type filter, such as available from Gast Manufacturing Co. of Benton Harbor, Mich. under model No. 8OV460.  
  The vacuum system 30 also includes a plurality of suction conduits 60 AC connected to the outlet side of the control valves 52 AC, respectively. The suction conduits 60 AC include movable ends which permit the conduits to be connected to the extinguisher 100 during the filling operation. Each of the conduits 60 AC are connected to one of the valves 52 AC through a filter and collector device 62 AC. The filters 62 AC are adapted to filter and collect large particles of the fire-suppressant material which may be drawn into the suction conduits 60 AC due to the operation of the vacuum-filling system 10. It has been found that a fiber jar-type filter, such as model AB609 by Gast Manufacturing Co. of Benton Harbor, Mich., is suitable as the filters 62 AC, 44 and 38. Thus, the filters 62 AC, combined with the filter 58, protect the vacuum system 30 from contamination by either small or large particles of the powdered material being charged into the extinguishers 100 during the operation of the system in accordance with this invention.  
  The filling system 10 also includes components which house a readily available supply of fire-suppressant material to be charged into the extinguishers 100 during the filling operation. The system 10 thus is provided with a plurality of material storage reservoirs 70 AC. As seen in FIG. 1, each of the reservoirs 70 AC is pivotally mounted upon a suitable frame structure 72 in a position adjacent the filling station 20. Each of the reservoirs 70 AC includes a removable cover plate 74, to contain the powdered material within the reservoirs during the operation of the system. The covers 74 can be removed from the reservoirs to fill the reservoirs 70 AC with a supply ofthe material to be employed in the system 10. The lower ends of the reservoirs 70 AC define conical discharge hoppers 76 AC. The hoppers 76 AC assist the gravity-feed of the powdered material from the reservoirs 70 AC during the filling operation. Filling conduits 78 AC are connected to the lower ends of each of the hoppers 76 AC, and have movable ends adapted to direct the material from each of the reservoirs 78 AC into the extinguisher 100.  
  The use of a plurality of reservoirs AC provides the system 10 with versatility, by permitting the system to be used to fill the extinguishers 100 with a variety of fire-suppressant materials, such as ABC powder, Purple K powder, or the standard BC powder, by supplying each reservoir 70 AC with a different type of powder. In addition, the reservoir lids 74 can be color-coded to simplify the identification of the different types of powders used in the system 10.  
  As seen in FIGS. 1 and 4 in the preferred arrangement the reservoirs 70 AC include a hinge 79 between the reservoirs and the supporting frame structure 72. The hinge 79 has a removable hinge pin 79A, and is designed to facilitate the charging of the powdery firesuppressant material into each of the reservoirs 70 AC. The construction of the hinge 79 permits the reservoirs 70 AC to be removed from the frame 72 and telescoped over an open barrel B of powdered material. Then, as shown in FIG. 4, the hinge pin 79A can be replaced, and the barrel B and the associated reservoir 70 AC can be easily pivoted about the hinge into the upright position shown in FIG. 1. The inverted barrel B will then be emptied into the reservoir 70 AC, and the cover 74 replaced. The telescoping of the barrel B within the reservoir prevents spillage of the powder from the barrel during the charging of the reservoirs 70 A-C.  
  The system 10 further includes a mechanism for coupling the movable ends of the filling conduits 78 AC and the suction conduits 60 AC together for insertion into the open orifice 102 of the fire extinguisher 100 to be filled. A sealing device is also provided to cooperate with the coupling mechanism, to temporarily seal the orifice of the extinguisher 100, during the vacuumfilling operation. Accordingly, as seen in FIGS. 1 and 2, the system 10 includes a plurality of pipe unions 80 which each couple one of the suction conduits 60 AC to one of the filling conduits 78 AC. The unions 80 include a material branch 80A and suction branch 808. One of the filling conduits 78 A-C is connected to the material branch 80A of each union in a sealed relationship. As seen in FIG. 2, each branch 80A includes an elongate material sleeve 82 which extends upwardly into the associated filling conduit 78 AC and downwardly through the union 80 into the interior of the extinguisher 100. In addition, the sleeve 82 operates in conjunction with union 80 to define an annular vacuum path 84, surrounding the sleeve 82 within the union. Spacers 84A maintain this annular path open. As seen in FIG. 2, the vacuum path 84 is in fluid communication with the suction branch 80B of the union 80. The union 80 thereby defines separate parallel flow passages for the vacuum flow and material flow during the operation of the filling system. The suction union 80B is connected, in an air-tight relationship, to one of the suction conduits 60 AC. The lower portion of the union 80 also includes external threads 86, or other suitable fastening means.  
  The system 10 in accordance with this invention further includes a sealing plug for joining the union 80 to a fire extinguisher in a sealed relationship with respect to the orifice 102. As shown in FIGS. 2 and 3, the sealing plug 90 is conical in configuration, and is constructed from a flexible material, such as an elastomer, which provides a resilient outer sealing surface for the plug. The plug 90 has a major base diameter 92 and a minor base diameter 94 which are selected so that the plug 90 will engage, in a sealing relationship, with a plurality of different-sized extinguisher orifices 102. This arrangement is accomplished by selecting the minor diameter 94 to be smaller than the anticipated minimum diameter of the extinguisher orifice 102 and by further selecting the major diameter 92 to be larger than the maximum anticipated diameter for the extinguisher orifice 102. In practice it has been found that a major plug diameter 92 of approximately 3 /2 inches, and a minor plug diameter 94 of approximately inches will adapt the plug 90 for sealing within the orifice 102 ofa plurality of conventional extinguishers 100 which are encountered in the field.  
  As clearly seen in FIG. 2, the axis of the conical plug 90 is provided with a bore 96. The upper portion of the bore 96 includes internal threads 98 which mate with the external threads 96 on the union 80, to seal the plug 90 in a fluid-tight arrangement with the union 80. The bore 96 receives the sleeve 82, and also defines an annular path around the sleeve 82 which connects with the vacuum line 60 AC through the annular path 84 and the suction branch 80B. The plug bore 96 thereby provides paths for the entry of the material from one of the conduits 78 A-C into the extinguisher 100 through the sleeve and for evacuating the interior of the extinguisher 100 through the suction branch 808.  
  The operation of the system in accordance with this invention is apparent from the above description. As explained above, the vacuum system operates automatically, through the vacuum switch 46, to maintain a selected vacuum pressure level within the vacuum tank 34. Accordingly, the extinguisher filling operation is started by placing an empty extinguisher 100 on the scale 24 at the filling station 20. Then, the operator of the system 10 selects the type of firesuppressant material which is to be drawn into the extinguisher 100 from the variety of materials provided in a separate material reservoir 70 AC. Assuming that the material contained within 70A is to be charged into the extinguisher 100, the operator then inserts the associated plug 90 and union 80 into the orifice 102 of the extinguisher 100. The interface between the extinguisher orifice 102 and plug 90 in this filling position is fully illustrated in FIG. 2. Next, the operator manually moves the control valve 52A from the closed position to the opened position, thereby coupling the suction conduit 60A to the vacuum system 30. Upon opening of the control valve 52A, the vacuum pressure within the vacuum system 30 creates a vacuum force to the interior of the extinguisher 100 through the line 60A, the suction branch 80B of the union 80, and the annular path 84. As illustrated by the arrows in FIG. 2, the air entrained within the extinguisher 100 is thereby evacuated from the extinguisher 100 along an upward flow path through the bore 96 in the plug 90. The creation of a vacuum pressure in the interior of the extinguisher 100 also assists in sealing the extinguisher 100 by creating a differetial pressure which draws the plug and the associated hopper 76A assists the movement of the material from the reservoir A by directing the material to the conduit 78A by the force of gravity. The material flows from the reservoir 70A through the filling conduit 78A and the sleeve 82 into the fire extinguisher 100. The extension of the sleeve 82 through the plug bore 96, and into the interior of the extinguisher minimizes the introduction of the powdered material into the vacuum system 30 during the operation of the system 10. The operator holds the control valve 52A open until the scale 24 indicates that the selected amount e.g., 10 pounds) of material has been charged into the extinguisher 100.  
  During the operation of the system 10, the air evacuated from the cylinder 100 by the vacuum system 30, including a small amount of entrained powdered material is drawn toward the vacuum system 30 by the negative pressure in the conduit 60A. This air with the entrained material, is passed through the filter 62A so that all larger particles of the material are collected in the filter 62A before the air reaches the valve 52A. The filter 62A is emptied periodically, and the material collected therein is returned to the associated material reservoir 70A. The returning evacuated air from the conduit 60A is filtered a second time by the tank filter 58, to remove any finer material particles before the air is returned to the vacuum storage tank 34. The dual filtering by the filters 62A and 58 also adapts the system 10 to handle a plurality of fire-suppressant materials having different particle sizes.  
  When the valve 52 is moved to a closed position, the suction force of the vaccum system 30 is stopped and the filling operation of the extinguisher 100 is completed. The extinguisher 100 is then removed from the filling station 20. The filling operation as described above can be repeated to fill additional extinguishers 100, having a variety of orifice sizes, with any type of material contained within the separate material storage reservoirs 70 A-C. The extinguisher 100 can be filled,  
 . in the same manner, with the material from the reservoir 70B by operation of the control valve 52B, and by coupling the free ends of the lines 60B and 78B with the extinguisher 100. Likewise, the extinguisher 100 can be filled with the material from the reservoir 70C by operation of the vacuum control valve 52C, and by coupling the lines 60C and 78C to the extinguisher.  
  Although the invention has been described above with a certain degree of particularity with respect to several embodiments, it should be understood that this disclosure has been made only by way of example. Consequently, numerous changes in the details of construction and in the combination and arrangement of the components as well as the possible modes of utilization for the extinguisher charging system in accordance with this invention will be apparent to those familiar with the art, and may be resorted to without departing from the scope of the invention.  
 What is claimed is:  
 l. A system for vacuum-filling a plurality of types of fire extinguishers having varying physical characteristics and requiring differing types of discrete fireretardant powdered material comprising:  
 a filling station for receiving a variety of empty fire extinguishers having varying capacities and an open orifice of differing diameters through which the extinguisher is to be filled;  
 a vacuum system including a vacuum source;  
 means providing a plurality of separate sources of different types of discrete fire-retardant material;  
 a plurality of filling conduits each having one end connectable in fluid communication with the discrete material from one of said sources and having a movable end connectable to the open orifice of the extinguisher to be filled at the filling station;  
 a plurality of vacuum conduits each having one end connectable to said vacuum source and having a movable end connectable to the open orifice of the extinguisher to be filled at the filling station;  
 coupling means joining one of said filling conduits to one of said vacuum conduits and adapted to simultaneously connect said coupled conduits with the open orifice of the extinguisher to be filled at said filling station;  
 sealing means joined to each pair of coupled conduits and adapted to seal each of said differing diameter extinguisher orifices from the surrounding atmosphere when said coupled conduits are secured within the orifice; and  
 material selection means for coordinating the type and volume of material discharged from said material sources with the type and capacity of the extinguisher at said filling station, said selection means including multiposition control valve means, arranged to provide each pair of coupled conduits with a valve movable to an opened position coupling the connected vacuum conduit to said vacuum source to create a partial vacuum with the extinguisher secured to said coupled conduits and rapidly flow discrete fire-retardant material from a selected one of said sources into said extinguisher through the coupled filling conduit, said valve in each pair of coupled conduits further being movable to a closed position to stop the flow of said selected discrete material through the coupled filling conduit when said extinguisher at said filling station is filled to capacity.  
  2. A system in accordance with claim 1 wherein said filling station for receiving an empty fire extinguisher includes weighing means so that operation of said system can be controlled to draw a selected weight of discrete fire-retardant material into the extinguisher.  
  3. A system in accordance with claim 1 wherein said vacuum system includes a sealed vacuum storage tank, pumping means to maintain a selected vacuum pressure within said tank. and a second vacuum conduit coupling said tank to said control valve means so that said tank provides a continuous vacuum force for filling a plurality of extinguishers successively, and further wherein said system includes a particle filter provided in each of said vacuum conduits to prevent discrete fire-retardant material from entering said vacuum storage tank and pumping means.  
  4. A system in accordance with claim 1 wherein each material source comprises a storage hopper having a downwardly converging floor section defining an outlet port for said material and wherein said filling conduit is coupled to said outlet port.  
  5. A system in accordance with claim 1 wherein said sealing means comprises a frusto-conical plug having a major base diameter larger than the maximum orifice diameter of said variety of extinguishers and a minor base diameter smaller than the maximum orifice diameter thereof so that said plug is dimensioned to be received within the varying orifices ofa plurality of extinguishers, said plug including a bore defining a flow conduit permitting the evacuation of said extinguishers and the flow of fire-retardant material into said extinguishers through said plug, and further including a resilent exterior conical surface which permits the evacuating of an extinguisher through said conduit to draw said exterior surface into secure sealing engagement with the orifice of the extinguisher being vacuum-filled, and coupling means extending through said bore and defining separate parallel passageways to separately connect the movable ends said vacuum and filling conduits in communication with the interior of the extinguisher.  
 6. A system for vacuum-filling a plurality of types of fire extinguishers having varying physical characteristics and requiring differing types of discrete fireretardant powdered material comprising:  
 a filling station for receiving a variety of empty fire extinguishers having varying capacities and an open orifice of differing diameters through which the extinguisher is to be filled;  
 a vacuum system including a vacuum source;  
 a plurality of separate reservoirs for housing a supply of different types of discrete fire-retardant material;  
 a plurality of filling conduits each having one end connectable in fluid communication with the discrete material in one of said reservoirs and having a movable end connectable to the open orifice of the extinguisher to be filled at the filling station;  
 a plurality of vacuum conduits each having one end connectable to said vacuum source and having a movable end connectable to the open orifice of the extinguisher to be filled at the filling station;  
 coupling means joining one of said filling conduits to one of said vacuum conduits and adapted to simultaneously connect said coupled conduits with the open orifice of the extinguisher to be filled at said filling station;  
 sealing means joined to each pair of coupled filling and vacuum conduits and adapted to seal each of said differing diameter extinguisher orifices from the surrounding atmosphere when said coupled pair of conduits is secured within the orifice;  
 material section means for coordinating the type and volume of material discharged from said reservoirs with the type and capacity of the extinguisher at said filling station, said selection means including a separate multi-position control valve for each of said vacuum conduits, with each valve movable between an opened position coupling the connected vacuum conduit to said vacuum source and creating a vacuum force in said connected vacuum conduit and a closed position which promptly eliminates said vacuum force in said connected vacuum conduit, so that selective movement of one of said control valves from said closed to said opened position with the coupled vacuum and filling conduits secured within a fire extinguisher orifice, draws a partial vacuum within said extinguisher through said vacuum conduit by means of said vacuum force and thereby creates a pressure differential which rapidly draws discrete fire-retardant material from a selected one of said reservoirs into the extinguisher through the coupled filling conduit, and further wherein the selective movement of one of said control valves from said opened position to said closed position promptly stops the flow of said fire-retardant material through the coupled filling conduit. into the extinguisher, when said extinguisher is filled to capacity, and promptly eliminates said vacuum force by venting said coupled filling conduit and said filled extinguisher to atmosphere pressure.  
  7. A system in accordance with claim 6 including a plurality of filter means provided in said vacuum system adapted to separately filter and collect said discrete material from each of said vacuum conduits and thereby prevent intermixing of said varying types of said material and contamination of said vacuum source.  
  8. A system for selectively vacuum-filling a plurality of types of fire extinguishers having varying physical characteristics and requiring differing types of discrete fire-retardant material comprising:  
 a filling station for receiving a variety of empty fire extinguishers having varying capacities and differing open orifice diameters through which the extinguisher is to be filled;  
 a vacuum system including a vacuum source;  
 means providing a plurality of separate sources of different types of discrete fire-retardant material;  
 filling conduit means having one end connectable in fluid communication with the discrete material in one of said material sources and having a movable end;  
 vacuum conduit means having one end connectable to said vacuum source and having a movable end; with the movable ends of said filling and vacuum conduit means being adapted for simultaneous connection with the open orifice of the extinguisher selected to be filled at said filling station;  
 sealing means joined to the movable ends of said filling and vacuum conduit means and sealing each of said differing diameter extinguisher orifices from the surrounding atmosphere when said movable ends of said filling and vacuum conduits are secured within the orifice of an extinguisher at the filling station; and  
 selection means for coordinating the type and volume of discrete fire retardant material to be discharged from said sources with the type and physical characteristics of an extinguisher at said filling station which is selected from a group of extinguishers having differing open orifice diameters, said selection means including valve means coupled to said vacuum conduit means and movable between an opened and a closed position with the movement of said valve means into said opened position creating a partial vacuum in the selected extinguisher at said filling station by coupling said extinguisher to said vacuum source through said vacuum conduit means and charging 5 selected one of said types of discrete fire-retardant material into said selected extinguisher from a selected material source through said filling conduit means, and with the movement of said valve means into said closed position coordinating the volume of said selected discrete material charged into said selected extinguisher with the capacity and type of extinguisher being filled through said filling conduit means by selectively reducing the partial vacuum within the extinguisher at said filling station and thereby reducing the flow of the selected discrete material from the selected source through said filling conduit means.  
  9. A system for filling fire extinguishers with discrete fire-retardant material in accordance with claim 8 wherein each of said material sources comprises a material reservoir which is readily charged from supply containers of discrete material including a hopper for receiving said discrete material, support means for said hopper, and pivotal connecting means operatively joining said hopper to said frame to align said hopper with a supply container of said material and pivot said hopper and aligned container together with respect to said frame and thereby charge said material to the hopper from the container.