Patent Publication Number: US-2005133529-A1

Title: Liquid feed system

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S)  
      This application is a continuation of U.S. patent application Ser. No. 10/292,734 filed Nov. 12, 2002 which is a continuation of U.S. patent application Ser. No. 09/546,104 filed Apr. 10, 2000, now issued as U.S. Pat. No. 6,502,721, and of U.S. patent application Ser. No. 09/545,126 filed Apr. 7, 2000, each of which is a continuation-in-part of U.S. patent application Ser. No. 09/102,858 filed Jun. 23, 1998, now issued as U.S. Pat. No. 6,129,245, which is a continuation-in-part of U.S. patent application Ser. No. 08/701,788 filed Aug. 26, 1996, now issued as U.S. Pat. No. 5,988,451. 
    
    
     FIELD OF THE INVENTION  
      This invention relates to a liquid feed system for dispensing liquids, typically liquid soaps or liquid lotions.  
     BACKGROUND OF THE INVENTION  
      Liquid feed systems for dispensing liquid soap and/or lotion provide convenience for the users of public and semi-public facilities. In addition to convenience, these systems allow individual users to dispense an appropriate amount of liquid to address their needs, thereby reducing waste and further eliminating sanitary concerns that might be introduced with publicly shared supplies, such as, for example, bar soap.  
      A typical liquid feed system includes a container for the soap and a manually operated valve which may be an off-on valve or a pump valve. Ordinarily the container is mounted directly on the valve structure. A variety of such liquid dispensers are in common use today.  
      When there are multiple wash basins, a liquid dispenser may be provided with every wash basin. Soap and/or lotion is provided to the liquid dispensers in a variety of manners. For instance, in some systems, each individual liquid dispenser has its own supply container. Dispensing systems utilizing an independent reservoir per liquid dispenser, however, have increased unit costs and maintenance costs.  
      In another type of liquid feed system, a plurality of liquid dispensers are served from a single container. In one such liquid feed system, sometimes referred to as a gravity soap system, a liquid reservoir is mounted on the wall above a plurality of basins, with a liquid dispenser positioned at each basin and fed by a line from the reservoir. The head pressure of the liquid in the container above the liquid dispensers causes the liquid to flow by gravity into each of the liquid dispensers to fill the valve cavity. Liquid is dispensed by actuating an open-shut valve to empty the valve cavity into the operator&#39;s hand. When the valve is closed, the cavity is refilled by the gravity flow from the reservoir. While this system works adequately when the reservoir is positioned directly above the liquid dispensers, it is not satisfactory when the reservoir is positioned at a distance from the liquid dispenser, below the liquid dispenser, or at the same level as the liquid dispenser, as liquid will not flow from the reservoir to the liquid dispenser. Also, of course, it requires that the reservoir be significantly above the liquid dispensers in order to produce the necessary head pressure.  
      In another configuration, sometimes referred to as an under-the-counter system, the reservoir is positioned directly under the counter. In these liquid feed systems the supply container is coupled to a single line or multiple lines that feed the individual pump-type liquid dispensers mounted above the counter. With this type of construction, the reservoir is filled by removing one of the liquid dispensers and pouring the liquid through the liquid dispenser housing into the reservoir below the counter. After the refill operation, each of the pump liquid dispensers must be primed by repeatedly actuating the pump mechanism. Typically about 75 to 110 strokes are required per liquid dispenser to adequately prime the liquid dispenser to start pumping.  
      A problem encountered by all of the above mentioned current liquid feed systems is that they fail to provide the liquid in an ongoing manner, namely, they fail to provide a continuous and uninterrupted supply of liquid for the users. Indeed, in situations wherein the liquid dispensers are refilled after they are empty, an interim period exists where some users will not be provided with the liquid. Of course, the supply reservoir can be replenished prior to becoming entirely empty, but this results in increased maintenance costs, and in instances where the supply reservoirs are sealed containers, the remaining liquid is wasted.  
      Although current liquid feed systems attempt to provide an ample supply of liquid, none of the current liquid feed systems address the issue of providing an economical and continuous, uninterrupted supply of liquid. Existing multiple valve, single reservoir liquid feed systems have several disadvantages. The valves are high cost, designed to withstand a high hydraulic head pressure. The piping system is made of costly metallic pipes either inside the wall, requiring early plumbing, or exposed non-esthetically pleasing plumbing. Also, the soap used has to be a water thin vegetable soap, to run in the pipes and meet the valve design criteria. Such soap, once popular, is now outdated and currently replaced with lotion-type soap, which is much more difficult to draw through the pipes. In addition, these liquid feed systems empty the supply line when the reservoir is empty. Thus, the lines must be reprimed. If the lines are long, more effort is required to reprime them.  
      Current liquid feed systems have increased maintenance costs and inconvenience to the end users. As such, a need exists in the industry for a liquid feed system that provides a relatively uninterrupted supply of liquid to the users. Further, a need exists for a liquid feed system that does not require repriming of the liquid dispensers if the supply is interrupted once the supply of liquid is replaced. Moreover, a need exists for a liquid feed system that dispenses the lotion-type soaps that are common today over long distances.  
     SUMMARY  
      The liquid feed system of the present invention is designed for use with a sealed, large capacity cleanser reservoir in the form of a flexible or collapsible fluid container. The collapsible fluid container provides the cleanser to a plurality of individual liquid dispensers, which may be attached directly to a wall, a countertop, or other support, with the liquid dispenser pump itself within a housing for improved vandal resistance. Inexpensive flexible tubing connects the collapsible fluid container to the individual liquid dispensers. The liquid feed system utilizes multi-viscosity, low cost, bulk liquid soap from containers which provide a month&#39;s supply. Actuation of a pump at the liquid dispenser deposits the liquid directly into the user&#39;s hand. The amount of cleanser in the collapsible fluid container can be periodically checked and the container replaced when the content falls to a predetermined level, or the container can be replaced periodically on a scheduled maintenance event.  
      Preferred embodiments of the invention include a liquid feed system for dispensing a liquid cleanser from a collapsible fluid container, with a plurality of liquid dispensers, each liquid dispenser having a positive displacement pump, and a flexible supply line for connecting the collapsible fluid container to each of the liquid dispensers.  
      One embodiment of the liquid feed system includes a cabinet with a container support positioned in the cabinet, an access door for removing a used collapsible fluid container and placing a new collapsible fluid container in the container support, and a lock for securing the access door on the cabinet. A nozzle is connected to the collapsible fluid container and a mating cap, coupled to the line, threadably engages the nozzle. In an alternative embodiment the collapsible fluid container may be placed in a remote room.  
      In another embodiment, the liquid dispensers are mounted on a wall and the supply line is behind the wall. The liquid dispensers may be mounted on a wall above a counter, with the collapsible fluid container supported below the counter, and with the supply line behind the wall, or hidden inside conduits on the wall, between the liquid dispensers and the collapsible fluid container. Alternatively the liquid dispensers may be mounted on a wall in a first room, with the collapsible fluid container in a second room, and with the supply line behind the wall between the liquid dispensers and the collapsible fluid container in the second room. In another alternative embodiment, the liquid dispensers may be mounted on a counter, with the collapsible fluid container under the counter, or in a storage room mounted at a height below the height of the counter.  
      The presently preferred embodiment of the liquid dispensers of the present invention is that shown in U.S. Pat. No. 5,476,197, which is incorporated by reference herein. In another embodiment of the liquid dispenser, the liquid dispenser includes a tubular casing with an inlet tube as the connection means for slidingly receiving an end of the flexible supply line and with a positive displacement pump slidably inserted into the casing. The positive displacement pump includes a cylinder with a piston cavity, a piston sliding in the piston cavity, an inlet opening in the cylinder for fluid flow from the flexible supply line through the inlet tube into the piston cavity, a spring in the piston cavity for urging the piston outward, a one-way valve positioned between the inlet opening of the cylinder and the spring, another one-way valve positioned between the spring and the piston, with the piston having an outlet flow passage defining a flow path from the flexible supply line through the casing inlet tube, cylinder, and piston cavity to the exterior of the liquid dispenser. Each of the liquid dispensers further include a pin that is fixed in the cylinder and rides in a slot in the piston. The pin permits the piston to slide within the piston cavity while limiting the travel of the piston and preventing piston rotation.  
      In an alternative embodiment, the liquid feed system includes a first collapsible container, a second collapsible container, and a connecting line, wherein the connecting line couples, in fluid communication, the first collapsible container to the second collapsible container, and further couples, in fluid communication, the first and second collapsible containers to liquid dispensers. The collapsible containers are positioned such that the first collapsible container is placed above the second collapsible container. An advantage of this configuration is that the liquid will fall due to gravity into the second collapsible container such that the additional liquid in the second collapsible container is not diminished, thereby eliminating the need to replace or refill the second collapsible container. Thus, the second collapsible container acts as a reserve to the first collapsible container. When the liquid held in the first collapsible container is depleted, the first collapsible container can be replaced while the second collapsible container remains in the liquid feed system to continuously supply additional liquid to the liquid dispensers without interruption.  
      The flow of liquid from the first and/or the second collapsible container can be controlled with a one-way valve, an adapter having a shut-off valve, diaphragm-type valve, or other valve that automatically caps off the connecting line when the collapsible container is disconnected from the rest of the liquid feed system. An advantage of this feature is that the connecting line remains filled with liquid, thereby eliminating the problem of repriming the liquid feed system whenever the liquid is replaced. Thus, the liquid feed system provides continuous service and immediate use without the need of repriming.  
      Liquid from the first and second collapsible containers is drawn into the liquid dispensers via an interconnection of connecting tubes, T-connectors, and elbow connectors. A first connecting tube couples an adapter connected to the first collapsible container to a first T-connector. Also, a second connecting tube couples an adapter connected to the second collapsible container to the first T-connector. A third connecting tube couples the first T-connector to a second T-connector. A fourth connecting tube couples the second T-connector to a first liquid dispenser. A fifth connecting tube couples the second T-connector to an elbow connector. A sixth connecting tube couples the elbow connector to a second liquid dispenser.  
      In accordance with one aspect of the present invention, a first connecting line couples, in fluid communication, the first collapsible container to the second collapsible container. Also, a second connecting line couples the second collapsible container, in fluid communication, to the liquid dispensers. In a more detailed aspect of the present invention, the first connecting line includes a connecting link adaptor having a first portion and a second portion matable to the first portion. The first portion is coupled, in fluid communication, to the first collapsible container, and the second portion is coupled, in fluid communication, to the second collapsible container. Also, the connecting link adaptor may be a quick-disconnect adaptor.  
      In another more detailed aspect of the present invention, the first portion of the connecting link adaptor includes a spring-activated shut-off valve that is actuated by connecting and disconnecting the first portion to the second portion. Liquid is permitted to flow through the first portion when the second portion is connected to the first portion, and is prevented from flowing flow out of the first portion when the first and second portions are disconnected. Thus, when the first collapsible container is removed, liquid is prevented from spilling out of the first collapsible container and the first collapsible container can easily be removed for servicing, replacement, or refilling.  
      In still another more detailed aspect of the present invention, the second portion of the connecting link adaptor includes a diaphragm-type valve that is actuated by connecting and disconnecting the second portion to the first portion. When the first collapsible container is disconnected, liquid is prevented from spilling out of the second collapsible container and air is prevented from entering the second collapsible container. Accordingly, the liquid feed system remains sealed and eliminates the need to reprime the liquid feed system when the first collapsible container is removed.  
      In another embodiment of the invention, a first connecting line couples, in fluid communication, the first collapsible container to the second collapsible container, and further, a second connecting line couples the second collapsible container, in fluid communication, to liquid dispensers. The second collapsible container includes a conduit strip. The conduit strip is configured with a plurality of conduit channels which provide for the flow of liquid through the second collapsible container even though the second collapsible container is collapsed. Thus, the conduit channels of the conduit strip protect against a blockage of the liquid feed system caused by a collapsed second collapsible container. Therefore, the conduit strip is useful when priming the liquid feed system for the first time and when priming an emptied second collapsible container.  
      In accordance with one aspect of the present invention, the configuration of the liquid dispensers and the second connecting line are modified. A first dispenser adapter is connected to the base of a first liquid dispenser and a second dispenser adapter is connected to the base of a second liquid dispenser. A first tube couples, in fluid communication, the second collapsible container to an inlet on the first dispenser adapter. A second tube is coupled between an outlet on the first dispenser adapter and an inlet on the second dispenser adapter. A third tube may couple an outlet on the second dispenser adapter to an inlet on a third dispenser adapter, or the outlet on the second dispenser adapter may be capped.  
      In another more detailed aspect of the present invention, a first container nozzle is connected to the first collapsible container. The first container nozzle is threadably engaged to one end of a first container mating cap. The other end of the first container mating cap couples to the first connecting line.  
      In a further embodiment of the present invention, in which the first collapsible container is in fluid communication with the second collapsible container, a lid is connected to a port in the second collapsible container. The lid includes an inlet connection tube in fluid communication with the first connecting line and an outlet connection tube, one end of which is in fluid communication with the liquid dispensers via the second connecting line. The other end of the outlet connection tube is coupled, in fluid communication, to a withdrawal tube which extends inside of the second collapsible container. A tube support is connected along the length of the withdrawal tube and positioned between the withdrawal tube and the interior surface of the second collapsible container. Accordingly, the configuration of the withdrawal tube and the tube support requires that the second collapsible container be filled with liquid to the elevation of the withdrawal tube, supported by the tube support, before liquid can flow out of the outlet connection tube.  
      A feature of the invention is the use of non-collapsible flexible tubing for the connecting lines. An advantage of this feature is that the collapsible containers can be placed in substantially any location without being limited by the placement of the tubing. A further advantage is that the non-collapsible tubing prevents the liquid from being completely drawn out of the line when the collapsible containers are empty, thereby, further eliminating the problem of repriming. Also, the collapsible containers of the instant invention can be of varying volumetric sizes, thus allowing the liquid feed system to accommodate a multitude of space configurations.  
      Other features and advantages of the present invention will be set forth in part in the description which follows and accompanying drawings, wherein the preferred embodiments of the present invention are described and shown, and in part will become apparent to those skilled in the art upon examination of the following detailed description taken in conjunction with the accompanying drawings, or may be learned by practice of the present invention. The advantages of the present invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view illustrating the liquid feed system of the invention with the collapsible fluid container mounted in a room separate from the wash basins and liquid dispensers.  
       FIG. 2  is a view similar to that of  FIG. 1  with the collapsible fluid container mounted underneath the counter.  
       FIG. 3  is an enlarged sectional view of the preferred embodiment of a liquid dispenser.  
       FIG. 4  is an enlarged sectional view of a liquid dispenser taken along the line  4 - 4  of  FIG. 2 .  
       FIG. 5  is a view similar to those of  FIGS. 1 and 2  with the liquid dispensers mounted on the counter adjacent the basin and the collapsible fluid container mounted underneath the counter.  
       FIG. 6   a  is an enlarged view of a portion of  FIG. 5  showing the installation of the collapsible fluid container and support box in the cabinet.  FIG. 6   b  depicts an alternative embodiment to  FIG. 6   a.    FIG. 6   c  is an enlarged partial sectional view taken along line  6 - 6  of  FIG. 6   b.    FIG. 6   d  is an enlarged sectional view of the connector of  FIGS. 6   b  and  6   c.    
       FIG. 7  is a schematic of a liquid feed system of the invention with both a first and second collapsible container.  
       FIG. 8  is an elevational view, partially in section, of an adapter including a piston utilized in the present invention.  
       FIG. 9  is a perspective view of the piston of  FIG. 8 .  
       FIG. 10  is a schematic view of another embodiment of a liquid feed system of the present invention, particularly illustrating a series-bag liquid feed system.  
       FIG. 11  is a schematic view of another embodiment of the liquid feed system of the present invention, particularly illustrating a second collapsible container with a conduit strip.  
       FIG. 12A  is a sectional view of the second collapsible container and conduit strip of  FIG. 11 .  
       FIG. 12B  is a top plan view of the conduit strip of  FIG. 11 .  
       FIG. 13A  is a schematic view of the embodiment of  FIG. 11  with a modified liquid dispenser and a second connecting line configuration.  
       FIG. 13B  is a schematic view of the embodiment of  FIG. 13A  with a modified interface between the first collapsible container and the first connecting line.  
       FIG. 14  is a schematic view of another embodiment of the liquid feed system of the present invention configured according to the present invention, particularly illustrating a series-bag liquid feed system with a withdrawal tube positioned inside of the second collapsible container.  
       FIG. 15  is an enlarged cross-sectional view of the withdrawal tube and tube support of  FIG. 14 .  
       FIG. 16A  is a schematic view of the embodiment of  FIG. 14  with a modified liquid dispenser and second connecting line configuration.  
       FIG. 16B  is a schematic view of the embodiment of  FIG. 16A  with a modified interface between the first collapsible container and the first connecting line.  
       FIG. 17  is a view similar to  FIG. 7  showing an alternate configuration for an auxiliary reservoir and fitting. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      One embodiment of a liquid feed system  10  of the present invention is illustrated in  FIG. 1  installed in a washing room  11  and a service room  12 . The washing room includes a conventional counter  13  with basins  14  and liquid dispensers  15 . A collapsible fluid container  16  is positioned in a support box  17  in the service room, and is connected to the liquid dispensers via a flexible line  18 , typically plastic tubing. The collapsible fluid container is located at an elevation below the liquid dispensers. The line has an airtight cap or other connection  21  for connection to the collapsible fluid container, and feeds liquid to each of the liquid dispensers through one or more tee fittings  22 . The presently preferred connection for connection  21  is that shown in U.S. Pat. No. 4,564,132, which is incorporated by reference herein.  
      In the embodiment illustrated, the liquid dispensers  15  are mounted on the wall  20  of the washing room  11  in position above and adjacent the basins  14 . The line  18  is positioned behind the wall and is connected to the liquid dispensers, as is shown in greater detail in  FIGS. 3 and 4 . The line runs up the wall and above the hung ceiling of the washing room and onward to the service room  12  for connection to the collapsible fluid container  16 . While two liquid dispensers are illustrated, the liquid feed system  10  can be used with one liquid dispenser and with more than two if desired.  
      An alternative configuration of the liquid feed system  10  is shown in  FIG. 2 . Where appropriate, the same reference numerals are used to avoid any unnecessary duplication and description of similar elements already referred to and described above. In  FIG. 2 , the support box  17   a  for the collapsible fluid container  16  (now shown) is positioned below the counter  13 . In the embodiments of both  FIGS. 1 and 2 , the support box  17 ,  17   a,  respectively, rests on a shelf, or in a cabinet, with or without a locked door, or on another article, or otherwise as desired.  
      The presently preferred embodiment of the liquid dispenser  15  is illustrated in detail in  FIG. 3 , however, other configurations for the liquid dispenser may be used. The presently preferred embodiment of the liquid dispenser is that shown in U.S. Pat. No. 5,476,197, which is incorporated by reference herein.  
      The liquid dispenser  15  of  FIG. 3  includes a positive displacement pump  28  which is manually operable or electrically powered, as desired. The liquid dispenser includes a casing  29  which is mounted to the counter  13  with the positive displacement pump positioned in a sleeve  36  within an opening  31  in the counter. The positive displacement pump also includes an inlet tube  30  for connection to the line  18 . The line is secured to the inlet tube by a fastener  32 .  
      The positive displacement pump  28  includes a cylinder  38 , and a piston  39  that slides within a piston cavity  40  inside of the cylinder. A spring  41  is positioned within the piston cavity. A first one-way valve  43  is positioned between the inlet tube  30  and the spring. A second one-way valve  44  is positioned in the end of the piston nearest the spring. The first and second one-way valves may be conventional in design, such as a duckbill valve or a capsule valve with head holding capacity.  
      In operation, moving the piston  39  downward, as viewed in  FIG. 3 , forces liquid from the piston cavity  40  out through the second one-way valve  44  and a passage  51  through the piston into the user&#39;s hand. When the pressure on the piston is released, the spring  41  moves the piston upward drawing liquid from the line  18  through the inlet tube  30  and into the piston cavity via the first one-way valve  43 .  
      The liquid dispenser  15  of the present invention is capable of other and different embodiments, and its several details are capable of modification. For example, another embodiment of a liquid dispenser configured according to the present invention is shown in  FIG. 4 . Where appropriate, the same reference numerals are used to avoid unnecessary duplication and description of similar elements already referred to and described above.  
      In the alternative embodiment shown in  FIG. 4 , the liquid dispenser includes a tubular casing  29  with an inlet tube  30  at one end for connection to the line  18 . The casing is mounted on the wall  20  with the inlet tube positioned in an opening  31  in the wall. The end of the line is fastened on the inlet tube by a fastener  32 . The casing is mounted on the wall by toggle bolts or screws or other fasteners  33  positioned in aligned openings  34  in the casing and aligned openings  35  in the wall. The openings are parallel with each other and perpendicular to the wall.  
      Each liquid dispenser  15  includes a positive displacement pump  28  which is manually operable or electrically powered, as desired. Also, the positive displacement pump may be a liquid pump or a lather pump as desired. The positive displacement pump includes a cylinder  38  with a piston  39  sliding in a piston cavity  40  inside of the cylinder. The cylinder includes a cavity wall  53  with an opening  52 . A spring  41  is positioned in the piston cavity. A first washer  42  is positioned within the piston cavity between the spring and a first one-way valve  43 . A second washer  45  is positioned within the piston cavity between the spring and a second one-way valve  44 . A seal ring  46  is positioned on the cylinder for sealing engagement with the interior wall of the casing  29 . Another seal ring  47  is provided in the piston for sealing engagement with the interior wall of the cylinder. A fastener, such as a screw  48 , provides for connecting the positive displacement pump to the casing. A pin  49  is fixed in the cylinder and rides in a slot  50  in the piston, permitting sliding of the piston in the cylinder while limiting the piston travel and preventing piston rotation, thereby keeping the soap outlet downwards.  
      In operation, moving the piston  39  inward or to the right as viewed in  FIG. 4 , forces liquid from the piston cavity  40  out through the second one-way valve  44  and a passage  51  through the piston into the user&#39;s hand. When the inward pressure on the piston is released, the spring  41  moves the piston outward, to the left as viewed in  FIG. 4 , which motion draws liquid from the line  18  through the inlet tube  30 , through the opening  52  in the cavity wall  53  of the cylinder  30 , and through the first one-way valve  43  into the piston cavity.  
      Since the liquid dispenser  15  does not operate with gravity flow, a construction of the liquid dispenser for preventing leakage at high head pressures it not required. The liquid dispenser as disclosed has a low cost simple construction. The cylinder  38  and piston  39  may be plastic molded parts and the rest of the entire positive displacement pump  28  requires only the spring  41 , washers  42 ,  45 , two one-way valves  43 ,  44 , seal rings  46 ,  47 , and the retaining screw  48  and pin  49 .  
      The casing  29  itself should be made from a high strength material to reduce damage due to vandalism. The casing typically is chrome plated die cast zinc for both durability and strength. Alternatively, a plated strong plastic material is used for the casing.  
      The line  18  is typically a flexible non-collapsible plastic tubing which is readily installed after the walls of the washing and service rooms are constructed.  
      In the embodiment shown in  FIGS. 5 and 6 , components corresponding to those of the earlier figures are identified by the same reference numerals to avoid unnecessary duplication and description of similar elements already referred to and described above. In this embodiment, the liquid dispensers  15  are mounted on the counter  13 , and a cabinet  55  is mounted underneath the counter for receiving the collapsible fluid container  16  and the support box  17 . The cabinet has a hinged door  56  with a locking latch  57  for controlling access to the cabinet.  
      In this embodiment, as illustrated in  FIG. 6   a , a nozzle  60  is carried on the support box  17  for connection to the collapsible fluid container  16 . The line  18  is connected to one end of a mating cap  62 , and the opposing end of the mating cap threadably engages the nozzle. While any nozzle and mating cap may be utilized, the presently preferred nozzle and mating cap are those of connection  21  in  FIG. 1 .  
      In an alternative embodiment illustrated in  FIGS. 6   b - 6   d , an outlet nozzle  60 ′ is carried in the support box  17 ′ for connection to the container  16 ′. A lever control valve  61 ′ may be affixed in the nozzle for controlling flow.  
      The flexible line  18 ′ is connected to the nozzle  60 ′ by a coupling  62 ′ with a J-shaped slot  63 ′ for engaging a pin  64 ′ at the outer end of the nozzle  60 ′. Typically a gasket  65 ′ is positioned in the coupling  62 ′ for sealing engagement with the end of the nozzle  60 ′.  
      A one-way valve  23 ′ may be positioned in the line  18 ′ in a fitting  24   a ′, with this fitting connected between portions  18   a ′ and  18   b ′ of the line by conventional barbed projections  66 ′.  
      With reference to  FIG. 7 , an alternative embodiment of a liquid feed system  10  of the present invention is shown. The liquid feed system includes a main reservoir  102 , an auxiliary reservoir  104 , a connecting line  105 , and two liquid dispensers  15 .  
      The main reservoir  102  includes a carton  107  having a top end  108 , a bottom end  110  and a hollow interior  112 . In practice, the main reservoir is positioned at an elevation below the elevation of the liquid dispensers  15 . A first collapsible container  114  is disposed within the carton. The carton includes a carton outlet  116  and a first outlet nozzle  117  through which liquid from the first collapsible container passes. The outlet nozzle is mounted in the carton outlet by conventional means, which permit the first outlet nozzle to rotate to achieve any desired orientation, e.g., vertically or horizontally.  
      The carton  107  is made from heavy cardboard, or any other material suitable for supporting therein a full soap container. In one embodiment, the main body of the carton is rectangular, although any shape which facilitates stable storage is suitable. In some embodiments, the carton further includes a handle  119  which is disposed on the top end  108  of the carton and a detachable box-end (not shown) for protection of the first nozzle  117 .  
      The first collapsible container  114  is made from a sturdy plastic material, although any nonpermeable material is suitable. In addition the first collapsible container can be made from “bacteria resistant” or antibacterial material such that microbes, spores or other germs or bacteria do not cultivate within the liquid.  
      The first collapsible container  114  is connected to a first outlet nozzle  117 , with a first outlet lever control valve  120  such as an on/off valve, which is well known in the art. The first outlet lever control valve controls the flow of the liquid from the first collapsible container through the first outlet nozzle. The first outlet nozzle is coupled to an outlet  122  of the first collapsible container, e.g., by welding, and is made from sturdy material, such as, but not limited to plastics or metal, although any material capable of facilitating the flow of liquids such as lotion-type soap or other similar liquids more viscous than water is suitable.  
      The auxiliary reservoir  104  is disposed below the main reservoir  102  and includes a second collapsible container  115 , having a second outlet nozzle  118 . The second collapsible container and the second outlet nozzle are of the same type as used in the main reservoir. The second collapsible container need not be encased in a carton since it is replaced less often than the first collapsible container  114 . The main and auxiliary reservoirs are placed on shelving or any other type of storage unit to protect the main and auxiliary reservoirs from being distributed or falling over. Typically, the auxiliary reservoir is placed between two shelves such that it is protected and the main reservoir resides on the shelf (not shown) above the auxiliary reservoir. The use of both the main and auxiliary reservoirs allows the main reservoir to be replaced when empty without affecting the supply of liquid to the end users as the auxiliary reservoir continues supplying additional liquid to the users. Preferably, a second outlet lever control valve  121  of the auxiliary reservoir, if provided, remains in the open position at all times, as the auxiliary reservoir need not be changed.  
      The first and second collapsible containers  114 ,  115  can accommodate any volumetric size. In one embodiment, the first collapsible container stores about 12 liters of liquid, and the second collapsible container is smaller and stores about 3 liters of additional liquid. The volumetric size of the main and auxiliary reservoirs  102 ,  104  is limited, in part, only by practical considerations, such as, for example, storage size and weight of the main and auxiliary reservoirs with the liquid. However, any varying sizes conducive to conveniently supplying liquid to end users is suitable.  
      An adapter  124  is mounted to the first and second outlet nozzles  117 ,  118  of the first and second collapsible containers  114 ,  115 , respectively. With reference to  FIG. 8 , the adapter includes a housing  126 , and a piston  128 . The housing  126  has a substantially cylindrical portion  130  having a first end  132 , an opposing second end  134 , and a barbed outlet  135 . The first end of the cylindrical portion is open and is sized to receive the first or second outlet nozzle  117 ,  118 . The first end further includes a J-shaped channel  136  that is configured to receive a nozzle pin  138  to form a bayonet-type connection such that the adapter and either the first or second outlet nozzle are coupled together. The second end of the cylindrical portion forms an annular wall  140 .  
      The barbed outlet  135  of the adapter  124  extends from the second end  134  of the cylindrical portion  130  of the housing  126  and includes a hollow body  142  having a bore  143  and an outer barbed surface  144 . The interior of the barbed outlet includes a flared opening  146  that widens toward the interior of the cylindrical portion. The cylindrical portion and the barbed outlet of the housing are manufactured as a unitary piece. The outer barbed surface facilitates coupling to a plastic tube. Other surface configurations, or other means capable of securing a tube to the adapter, such as a clamp, however, are also suitable.  
      With reference also to  FIG. 9 , the piston  128  includes a shaft  148  having a plug  150  mounted at one of the opposing ends of the shaft. The shaft includes four ribs  152  that come together at their inner ends to form the shape of a cross. Each rib has a first end portion  154  that extends longitudinally from the plug  150  and has a width slightly smaller than the radius of the bore  143  of the barbed outlet  135  such that the first end portions of the four ribs form a cross-shaped first end portion  156  that fits within the bore of the barbed outlet and provides flow passages between the ribs through the barbed outlet.  
      Each rib  152  also has a tapered portion  158  that flares out from the first end portion  154 . The four tapered portions form a cross-shaped tapered portion  160  that mates with the flared opening  146  of the housing  126 . Further, each rib has a radially extending shoulder portion  162  and a second end portion  164 . As shown in  FIG. 8 , a spring  166  is located between and engages the radial extending shoulder portions of the ribs and the annular wall  140  of the housing to bias the piston  128  towards the first end  132  of the cylindrical portion  130  of the housing.  
      The second end portions  164  of the four ribs  152  form a cross-shaped second end portion  168  that closely fits within the cylindrical portion  130  of the housing  126  and provides flow passage between the ribs and the cylindrical portion.  
      The plug  150  is a disc-shaped member that fits within the bore  143  of the barbed outlet  135 . A peripheral groove  170  in the plug receives an O-ring  172  to form a seal between the plug and the bore of the barbed outlet to prevent liquid from leaking out of the adapter  124 . The shaft  148  and the plug can be manufactured as a single unitary piece.  
      The adapter  124  is mounted, for example, to the first outlet nozzle  117  of the first collapsible container  114  by placing it over the end of the first outlet nozzle such that the nozzle pin  138  of the first outlet nozzle enters the J-shaped channel  136  of the adapter. As the adapter is mounted to the first outlet nozzle, the end of the first outlet nozzle engages the cross-shaped second end portion  168  of the piston  128  and slides it downward, disengaging the O-ring  172  from the bore  143  of the barbed outlet  135 , permitting liquid to flow through the adapter when the first outlet lever control valve  120  is opened. The adapter is secured to the first outlet nozzle by rotating the adapter such that the nozzle pin of the first outlet nozzle is located in the circumferentially extending portion  169  of the J-shaped channel. Notably, when it is time to replace an empty first collapsible container with a full container, the adapter is disengaged from the first outlet nozzle and the plug  150  of the piston automatically retracts into the bore of the adapter due to the biasing action of the spring  166 . This prevents liquid from the liquid dispenser  15  and connecting line  105  from leaking back out through the adapter. Similarly, the adapter may be mounted to the second outlet nozzle  118  of the second collapsible container  115 .  
      It is to be appreciated that in some embodiments, the auxiliary reservoir  104  need not utilize the adapter  124 , but rather the second outlet nozzle  118  may be modified such that it directly couples with the connecting line  105 . As stated above, there is less of a need to be able to control the flow of liquid into the auxiliary reservoir as it is not changed as often as the main reservoir  102 .  
      With reference again to  FIG. 7 , a first connecting tube  200  is coupled between the adapter  124  on the main reservoir  102  and a first inlet  202  of a first T-connector  204 . A second connecting tube  206  is coupled between the adapter on the auxiliary reservoir  104  and a second inlet  208  of the first T-connector. A third connecting tube  210  is coupled between an outlet  212  of the first T-connector and a first inlet  214  of a second T-connector  216 . A fourth connecting tube  218  is coupled between a first outlet  220  of the second T-connector and an inlet  221  to a first liquid dispenser  222 . A fifth connecting tube  224  is coupled between a second outlet  226  of the second T-connector and an inlet  228  to a second liquid dispenser  230 . Alternatively, the fifth connecting tube may be coupled between the second outlet of the second T-connector and an inlet  231  of an elbow connector  232 , and a sixth connecting tube  234  may be coupled between an outlet  236  of the elbow connector to the inlet of the second liquid dispenser. All of the connecting tubes are made from a flexible material that does not collapse during use. It will also be appreciated that many different types of fittings, such as tees, elbows, cross fittings, etc. may be used depending on the application. In addition, reducers may be inserted in the connecting tubes to connect any size collapsible container to any size liquid dispenser.  
      In practice, once the main and auxiliary reservoirs  102 ,  104  are located in a facility, e.g., a restroom, the adapters  124  are connected to the first and second outlet nozzles  117 ,  118  of the first and second collapsible containers  114 ,  115 , respectively, and the liquid dispensers  15  are initially primed such that liquid fills the connecting tubes  200 ,  206 ,  210 ,  218 ,  224 ,  234 . When an end user operates a liquid dispenser, liquid is drawn from the connecting tubes through the liquid dispenser and into the end user&#39;s hands.  
      Typically, due to gravity, liquid from the main reservoir  102  moves downward into the auxiliary reservoir  104  such that the auxiliary reservoir remains full of additional liquid. The liquid is drawn from both the main and auxiliary reservoirs through the first T-connector  204  via the first connecting tube  200  and the second connecting tube  206 . The liquid is drawn through the first T-connector and traverses the connecting tubes  210 ,  218 ,  224 ,  234  until it reaches the liquid dispensers  15 .  
      Typically, the main reservoir  102  will empty before the auxiliary reservoir  104 . After the main reservoir is empty, maintenance personnel will disconnect the adapter  124  from the first outlet nozzle  117  on the main reservoir and remove the main reservoir from the location. As the adapter is removed from the first outlet nozzle, the piston  128  ( FIG. 8 ) slides toward the first end  132  of the housing  126  such that the O-ring  172  retracts and seals the bore  143  of the barbed outlet  135 , and thereby preventing any back flow of the liquid out of the first connecting tube  200  and adapter. Removal of the main reservoir does not affect operation of the liquid feed system  10 . Rather, the liquid dispensers  15 , when operated, begin drawing additional liquid from the auxiliary reservoir until such time that the main reservoir has been replaced. Thus, the end user is unaware of the removal of the main reservoir. Finally, the main reservoir is replaced and the auxiliary reservoir is replenished from the main reservoir by gravity. The auxiliary reservoir allows for continuation of service even if the main reservoir is empty and while the main reservoir is being replaced.  
      If the demand for liquid exceeds capacity, and both the main and auxiliary reservoirs  102 ,  104  become empty, the liquid dispensers  15  will stop delivering liquid but the connecting tubes  200 ,  206 ,  210 ,  218 ,  224 ,  234  will remain filled with liquid that cannot be dispensed since the first and second collapsible containers  114 ,  115  are airtight. Therefore, the liquid feed system  10  will remain primed. This is a feature that allows immediate dispensing from the liquid dispensers as soon as the empty main and auxiliary reservoirs are replaced, provided both the main and auxiliary reservoirs are connected to an adapter  124  that seals the end of the first and second connecting tubes  200 ,  206  as each reservoir is replaced. After replacement of the main and auxiliary reservoirs, the newly supplied liquid simply allows the liquid already in the connecting tubes to be dispensed first.  
      The construction of the invention readily permits the use of large capacity fluid containers, including the twelve and twenty-four liter containers now used for soap supplies. The ability to replace the first and second collapsible containers  114 ,  115 , is a maintenance time saving feature since no bulk soap is poured and possibly spilled, and only one container need be replaced to fill multiple liquid dispensers  15 .  
      The present invention is capable of other and different embodiments, and its several details are capable of modification. For example, another embodiment of a liquid feed system  10  configured according to the present invention is shown in  FIG. 10 . Where appropriate the same reference numerals are used to avoid unnecessary duplication and description of similar elements already referred to and described above. Only the significant differences of the embodiment will be discussed hereafter.  
      A series-bag liquid feed system  300  supplies liquid, such as, soap or lotion, to liquid dispensers  15 . The liquid feed system  300  primarily comprises a first collapsible container  114 , a second collapsible container  115  which has a wall  314  and an interior surface  316 , a first connecting line  301  that couples, in fluid communication, the first collapsible container to the second collapsible container, and a second connecting line  303  which couples, in fluid communication, the second collapsible container to the liquid dispensers.  
      The first collapsible container  114  is at an elevation that is below the elevation of the liquid dispensers  15  and above the elevation of the second collapsible container  115  such that the liquid is drawn from the first collapsible container, through the first connecting line  301 , and into the second collapsible container. Thus, the second collapsible container holds additional liquid and acts as a reserve to the first collapsible container. When the liquid held in the first collapsible container is depleted, the first collapsible container can be replaced while the second collapsible container remains connected, to continuously supply liquid to the liquid dispensers without interruption.  
      In a detailed aspect of the present embodiment of the invention, the first connecting line  301  includes a connecting link adaptor  302  having a first portion  304  and a second portion  306  matable to the first potion. The first portion is coupled, in fluid communication, to the first collapsible container  114 , and the second portion is coupled, in fluid communication, to the second collapsible container  115 . The connecting link adaptor can be a high-flow quick-disconnect adaptor of a type commercially available, such as, model number HFCD176-12 for the first portion (base with quick release) and model number HFCD226-12 for the second portion (mating portion) manufactured by Colder Products Company and distributed by Ryan Herco of Burbank, Calif.  
      Use of the connecting link adaptor  302  allows for easy removal of the first collapsible container  114  for servicing, replacement, or refilling. Further, the connecting link adaptor as used in this embodiment eliminates the need for certain parts used in other embodiments, such as, an adaptor  124  for the second collapsible container  115 , a T-connector  204 , and a second outlet lever control valve  121  for the second collapsible container.  
      The first portion  304  of the connecting link adaptor  302  can include a diaphragm-type valve that is actuated by connecting and disconnecting the first portion to the second portion  306 . Liquid is permitted to flow through the first portion when connected to the second portion, and prevented from flowing out of the first portion when disconnected from the second portion. Thus, when the first collapsible container  114  is removed, liquid is prevented from spilling out of the first collapsible container.  
      The second portion  306  of the connecting link adaptor  302  can also include a spring-actuated shut-off valve that is actuated by connecting and disconnecting the second portion to the first portion  304 . When the first collapsible container  114  is removed, the spring-actuated shut-off valve prevents liquid from spilling out of the second collapsible container  115  and air from entering the second collapsible container. Accordingly, the liquid feed system  10  remains sealed and eliminates the need to reprime the liquid feed system when the first collapsible container is removed.  
      Another embodiment of the present invention is shown in  FIG. 11 . Where appropriate the same reference numerals are used to avoid unnecessary duplication and description of similar elements already referred to and described above. Only the significant differences of the embodiment will be discussed hereafter.  
      The embodiment of the series-bag liquid feed system  300 , shown in  FIG. 11 , primarily comprises a first collapsible container  114 , a second collapsible container  115 , a first connecting line  308 , a second connecting line  303 , and two liquid dispensers  15 .  
      The first collapsible container  114  is at an elevation below the liquid dispensers  15  and above the second collapsible container  115 , which holds additional liquid and acts as a reserve to the first collapsible container. Similar to the previous embodiment, when the first collapsible container is empty, the first collapsible container can be replaced without removing the second collapsible container from the series-bag liquid feed system  300 .  
      The second collapsible container  115  includes a wall  314 , an interior surface  316 , an inlet nozzle  319 , and an outlet nozzle  321 . Both the inlet and outlet nozzles are connected to the wall of the second collapsible container and positioned at opposite ends of the second collapsible container.  
      The first connecting line  308  includes a first end  310  and a second end  312 . The first end of the first connecting line is coupled, in fluid communication, to the first collapsible container  114  via an adapter  124 , and the second end is coupled, in fluid communication, to one end of an inlet mating cap  318 . The opposing end of the inlet mating cap threadably engages the inlet nozzle  319 . The second connecting line  303  couples, in fluid communication, one end of an outlet mating cap  320  to the liquid dispensers  15 . The opposing end of the outlet mating cap threadably engages the outlet nozzle  321 .  
      The conduit strip  322  includes a plurality of conduit ridges  326  and a plurality of conduit channels  328 , as shown in  FIGS. 12A and 12B . Each conduit channel is defined by a pair of conduit ridges. The conduit strip is bonded, preferably with tape, to the interior surface  316  of the second collapsible container  115 . The conduit strip is positioned such that when the second collapsible container is collapsed the outlet nozzle  321  is adjacent to one end of the conduit strip while the opposing end of the conduit strip overlaps the inlet nozzle  319 .  
      The conduit channels  328  prevent clogging of the outlet nozzle  321  when the second collapsible container  115  is collapsed. If a second collapsible container, without a conduit strip, is collapsed there exists a possibility that the outlet nozzle would come in contact with the interior surface  316  of the second collapsible container. If a user attempts to actuate the liquid dispenser  15  when the outlet nozzle is in contact with the interior surface of the second collapsible container, a vacuum could develop in the second connecting line  303 . This vacuum would help to maintain the contact between the outlet nozzle and interior surface of the second collapsible container and cause a blockage of the series-bag liquid feed system  300  resulting in no flow or a reduced flow of liquid to the liquid dispensers.  
      In contrast, a collapsed second collapsible container  115 , configured with the conduit strip  322 , would have a reduced likelihood of blockage because the conduit ridges  326  would contact the outlet nozzle  321 , and the conduit channels  328  would allow for liquids, such as, soap or lotion, to flow through the outlet nozzle and into the second connecting line  303 . The protections against blockage of the series-bag liquid feed system  300  provided by the conduit strip are useful when priming the liquid feed system  10  for the first time and when priming an emptied second collapsible container.  
       FIG. 13A  is a depiction of another embodiment of the invention shown in  FIG. 11 . Where appropriate the same reference numerals are used to avoid unnecessary duplication and description of similar elements already referred to and described above. Only significant differences of the embodiment will be discussed hereafter. In  FIG. 13A , the configuration of the liquid dispensers  15  in  FIG. 13A  is modified from that of  FIG. 11 .  FIG. 13A  shows a first dispenser adapter  253  connected to the base of a first liquid dispenser  254 . Similarly, a second dispenser adapter  261  is connected to the base of a second liquid dispenser  262 . Also, the second connecting line  303  has a modified configuration. With reference to  FIG. 13A , a first tube  250  is coupled between the outlet mating cap  320  and an inlet  252  of the first dispenser adapter. A second tube  256  is coupled between an outlet  258  of the first dispenser adapter and an inlet  260  of the second dispenser adapter. A third tube  264  may be coupled between an outlet  266  of the second dispenser adapter and an inlet (not shown) of a third dispenser adapter (not shown). If a third tube is not utilized, the outlet of the second dispenser adapter is sealed with a cap (not shown).  
      In operation, the liquid dispensers  15  draw liquid from the second collapsible container  115  via the first tube  250 . Specifically, a user of the first liquid dispenser  254  draws liquid from the first tube into the first liquid dispenser via the inlet  252  of the first dispenser adapter  253 . A user of the second liquid dispenser  262  draws liquid from the outlet  258  of the first dispenser adapter into the second liquid dispenser via the second tube  256  and the inlet  260  of the second dispenser adapter  261 .  
       FIG. 13B  is a depiction of another embodiment of the invention shown in  FIG. 13A . Where appropriate the same reference numerals are used to avoid unnecessary duplication and description of similar elements already referred to and described above. Only significant differences of the embodiment will be discussed hereafter. In  FIG. 13B , the first collapsible container  114  is disposed within the carton  107 . A first container nozzle  123  is carried on the carton and is coupled to the outlet  122  of the first collapsible container. One end of a first container mating cap  125  threadably engages the first container nozzle, and the opposing end of the first container mating cap is connected to the first end  310  of the first connecting line  308 . While any nozzle and mating cap may be utilized, the presently preferred nozzle and mating cap for the first container nozzle and first container mating cap are those of connection  21  in  FIG. 1 .  
      When the first container mating cap  125  engages the first container nozzle  123 , liquid flows from the first collapsible container  114  through the first container nozzle and first container mating cap into the first connecting line  308 . In contrast, when the first container mating cap is disengaged from the first container nozzle, the flow of liquid out of the first collapsible container stops and the first connecting line remains sealed.  
      A further embodiment of the present invention is shown in  FIG. 14 . Where appropriate the same reference numerals are used to avoid unnecessary duplication and description of similar elements already referred to and described above. Only the significant differences of the embodiment will be discussed hereafter.  
      The embodiment of the series-bag liquid feed system  300 , shown in  FIG. 14 , similar to the embodiment of  FIG. 11 , primarily comprises a first collapsible container  114 , a second collapsible container  115 , a first connecting line  308 , a second connecting line  303 , and two liquid dispensers  15 .  
      As stated in the embodiment of  FIG. 11 , the first collapsible container  114  is at an elevation below the liquid dispensers  15  and above the second collapsible container  115 , which holds additional liquid and acts as a reserve to the first collapsible container. Also, the first collapsible container can be replaced without removing the second collapsible container from the series-bag liquid feed system  300 .  
      The second collapsible container  115  includes a wall  314 , an interior surface  316 , a port  330 , a lid  332 , an inlet connection tube  334 , an outlet connection tube  336 , a J-shaped tube  338 , a withdrawal tube  340 , and a tube support  342 . The port is positioned through the wall of the second collapsible container. The lid connects to the port forming an airtight seal between the lid and the port. The lid includes the inlet connection tube and outlet connection tube. One end of the J-shaped tube is coupled, in fluid communication, to an end of the outlet connection tube, while the other end of the J-shaped tube is coupled, in fluid communication, to the withdrawal tube. The tube support is H-shaped in cross section and connected to the withdrawal tube, along its length, as shown in  FIGS. 14 and 15 . The tube support helps to hold the withdrawal tube in a horizontal position and to provide a spacer between the interior surface of the second collapsible container and the withdrawal tube.  
      The first connecting line  308  includes a first end  310  and a second end  312 . The first end is coupled, in fluid communication, to the first collapsible container  114 , and the second end is coupled, in fluid communication, to the inlet connection tube  334  of the second collapsible container  115 . In addition, the second connecting line  303  couples, in fluid communication, one end of the outlet connection tube  336  to the liquid dispensers  15 .  
      In the embodiment of the present invention shown in  FIGS. 14 and 15 , liquid flows from the first collapsible container  114  through the first connecting line  308  and inlet connection tube  334 , into the second collapsible container  115 . Liquid leaves the second collapsible container after passing through the withdrawal tube  340 , the J-shaped tube  338 , and the outlet connection tube  336 . In this configuration, liquid entering the second collapsible container must fill the second collapsible container to the elevation of the withdrawal tube before it is allowed to exit the second collapsible container. This feature is advantageous in that it forces liquid to fill at least a portion of the second collapsible container and not just flow directly from the inlet connection tube to the outlet connection tube.  
       FIG. 16A  is a depiction of another embodiment of the invention shown in  FIG. 14 . Where appropriate the same reference numerals are used to avoid unnecessary duplication and description of similar elements already referred to and described above. Only significant differences of the embodiment will be discussed hereafter. In  FIG. 16A , the second connecting line  303  has a modified configuration similar to that of the embodiment of the invention in  FIG. 13A .  FIG. 16A  shows a first dispenser adapter  253  connected to the base of a first liquid dispenser  254 . Similarly, a second dispenser adapter  261  is connected to the base of a second liquid dispenser  262 . With reference to  FIG. 16A , a first tube  250  is coupled between the outlet connection tube  336  and an inlet  252  of the first dispenser adapter. A second tube  256  is coupled between an outlet  258  of the first dispenser adapter and an inlet  260  of the second dispenser adapter. A third tube  264  may be coupled between an outlet  266  of the second dispenser adapter and an inlet (not shown) of a third dispenser adapter (not shown). If a third tube is not utilized, the outlet of the second dispenser adapter may be sealed with a cap (not shown). The flow of liquid into the first and second liquid dispensers is similar to that discussed for the embodiment in  FIG. 13A .  
       FIG. 16B  is a depiction of another embodiment of the invention shown in  FIG. 16A . Where appropriate the same reference numerals are used to avoid unnecessary duplication and description of similar elements already referred to and described above. Only significant differences of the embodiment will be discussed hereafter. In  FIG. 16B , the first collapsible container  114  is disposed within the carton  107 . A first container nozzle  123  is carried on the carton and is coupled to the outlet  122  of the first collapsible container. One end of a first container mating cap  125  threadably engages the first container nozzle, and the opposing end of the first container mating cap is connected to the first end  310  of the first connecting line  308 . While any nozzle and mating cap may be utilized, the presently preferred nozzle and mating cap for the first container nozzle and first container mating cap are those of connection  21  in  FIG. 1 . The flow of liquid through the first container nozzle and first container mating cap is the same as that of the embodiment of  FIG. 13B .  
      Advantages of the liquid feed system  10  of the present invention include the following. The liquid feed system delivers liquid, such as, soap or lotion, through liquid dispensers  15  which can be mounted directly to the wall  20  or a counter  13 , without costly stainless steel soap vessels attached to them. Since the liquid feed system has no expensive vessels with which to tamper, the liquid feed system is inexpensive and essentially vandal proof. Also, the liquid feed system can handle a wide range of soap viscosity from water thin to shampoo-like thicknesses. In addition, the liquid feed system is hygienic and poses no threat of contamination. Moreover, this low-cost installation and maintenance liquid feed system is especially suitable for use in fast food restaurants and other facilities with high public traffic where frequent interruptions for servicing the liquid feed system is undesirable.  
      Another advantage of the liquid feed system  10  is that it has a centrally-located collapsible fluid container  16 , or first and second collapsible containers  114 ,  115 , for supplying all of the liquid dispensers  15 . A single refill or replacement of the centrally-located fluid container(s) will supply the complete washing room  11 . Also, the centrally-located fluid container(s) can be mounted on the floor level, under the counter, or in a remote area. In addition, the line  18  or connecting tubes  200 ,  206 ,  210 ,  218 ,  224 ,  234 ,  250 ,  256 ,  264 ,  301 ,  308  of the liquid feed system are non-collapsible and will remain filled with liquid at all times for quick priming since the liquid dispensers will stop delivery of liquid once the centrally-located container(s) are empty.  
      Another embodiment of the liquid feed system is shown in  FIG. 17  wherein the washing system has parallel reservoirs. In this configuration the first reservoir is positioned above the second reservoir and the fitting is preferably positioned below the second reservoir. An advantage of positioning the fitting below the second reservoir is that air present in the first reservoir will not be drawn into the fitting when the first reservoir is empty and dispensing liquid is being drawn from the second reservoir. This eliminates the need to reprime the system in order to draw dispensing liquid from the second reservoir, after the first reservoir is emptied.  
      In an alternative embodiment, a small diameter tubing connects the second reservoir to the fitting. The small diameter tubing has a smaller internal diameter than the tubing connecting the first reservoir to the fitting. An advantage of this feature is that the dispensing fluid is drawn more easily from the first reservoir thereby preventing the lower reservoir from diminishing until after the first reservoir is completely empty.  
       FIG. 17  illustrates an alternative embodiment of the configuration shown in  FIG. 7 . In this embodiment, the outlet nozzle  118 ′ is located on the bottom of the collapsible soap container  115 ′ of the secondary reservoir  104 ′. As with the configuration shown in  FIG. 7 , connecting tube  206 ′ is coupled between the adapter  124 ′ on the outlet nozzle  118 ′ of the collapsible soap container  115 ′ of the secondary reservoir  104 ′ and a second inlet  208 ′ of the first T-connector  204 ′. However, as shown in  FIG. 17 , the first T-connector  204 ′ is positioned so that it is below the bottom of the secondary reservoir  104 ′. The first connecting tube  200 ′ is extended to couple with the first inlet  202 ′ of the first T-connector  204 ′. With the first T-connector  204 ′ below the secondary reservoir  104 ′, dispensing liquid will remain in the first connecting tube  200 ′ after the first reservoir  102 ′ is empty and the dispensing fluid is being drawn from the secondary reservoir  104 ′. Fluid remains in the first connecting tube  200 ′ due to the head pressure of the dispensing liquid in the secondary reservoir  104 ′. This configuration prevents any air that may be present in the collapsible soap container  114 ′ of the first reservoir  102 ′ from entering the connecting line  105 ′ and necessitating that the washing system  100 ′ be reprimed.  
      It is to be appreciated that the outlet nozzle  118 ′ need not be located on the bottom of the collapsible soap container  115 ′ of the secondary reservoir  104 ′, in order to configure the washing system so that the first T-connector  204 ′ is positioned below the secondary reservoir.  
      In an alternative embodiment of the configuration shown in  FIGS. 7 and 17 , the second connecting tube  206 ′ has a smaller inner diameter than the first connecting tube  200 ′. The smaller diameter of the second connecting tube  206 ′, known as a restrictive tube, reduces the volume of dispensing fluid that can be drawn through the tube and also increases the forces necessary to draw fluid through the secondary tube relative to the larger first connecting tube  200 ′ because of increased viscous forces. Restricting the flow of dispensing fluid from the secondary reservoir  104 , further ensures that the secondary reservoir does not diminish until the first reservoir  102  is empty which is one of the advantages of the two reservoir configuration.  
      Those skilled in the art will recognize that other modifications and variations can be made in the liquid feed system  10  of the present invention and in construction and operation of this liquid feed system without departing from the scope or spirit of this invention.