Abstract:
The dual chamber dispenser consists of two tubular chambers each of which is connected to a pump. The pumps are self-priming and are of a type that draw the substances from the tubular chambers. There is an activator which also serves as the top of the dispenser, side view apertures, a foot for better stability and a spout that is angled for enhanced dispensing. The side view apertures allow for viewing the fill level of the tubular chambers. The pumps are of a type having an upper valve and a lower valve, with the upper valves a part of the piston&#39;s that move in and out of the pumping chambers. The valves in said pumps are positive closing by means of a biasing spring. The substances to be dispensed are maintained separate, one from the other, until the substances are dispensed.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/001,612 filed Jul. 28, 1995. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to multi-chamber pump dispensers for various products. More particularly, this invention relates to multi-chamber pump dispensers which can dispense the same quantities of viscous materials having differing rheologies. Further this invention relates to a multi-chamber dispenser which utilizes membrane closures for the segregated dispensing of substances. 
     BACKGROUND OF THE INVENTION 
     There are various substances which are not compatible. When they are to be used together they must be packaged separately. This can be in two or more fully separate containers, two or more separate containers that are held together by interfitting sections or by means of a tie band, or two or more compartments of a single container. The most cost effective packages are single unitary packages which have a plurality of chambers. These are the most stable in handling and use. Also, they usually will be more compact and will require less material of manufacture. However, a problem with these various packages is the uniform dispensing of the substances from each of the compartments. 
     One area where multiple chamber containers are useful is in packaging and dispensing pastes such as dentifrices. In dentifrice formulations there can be components that are not highly compatible. These can be basic components and acidic components that are used to produce effervescence in a dentifrice. Likewise, these can be components such as baking soda and a peroxide such as hydrogen peroxide, or an organic peroxide such as urea peroxide These components cannot be packaged in a common container. They must be kept separate until ready for use. The use of dual chamber dispensers solves the problem of keeping such components separate and in addition provides a method for dosing the approximate amount of each component. Another area of use is in dispensing adhesives such as epoxy adhesives. The two reactive components can be kept separate until the time of use. They are then dispensed and promptly used prior to reactively hardening. 
     The state-of-the-art of dual chamber dispensers for dentifrices is disclosed in several United States Patents. In U.S. Pat. No. 4,773,562 there is disclosed the separate storage of two components in pressurized containers. There is a common activator for these containers and a mixing chamber prior to the paste being dispensed. U.S. Pat. Nos. 5,020,694; 5,078,963; 5,332,124 and 5,335,827 are a series of patents directed to embodiments of the same dual chamber dispenser. In this dual chamber dispenser the dispensing is activated by a manual force of pushing pistons mounted on piston rods upward into dual chambers that contain the substances to be dispensed. These patents also are directed to the structure necessary to maintain the substances separate until dispensed, having the two substances converge when dispensed, the containment structure, and the refill structure. However, the dispenser in each of these patents is conceptually the same dispenser and is activated by a manual force on piston rods that is transferred to a piston in each chamber. 
     Dual chamber dispensers also are exemplified by the pump dispenser disclosed in U.S. Pat. No. 5,224,627. This patent discloses a dual chamber dispenser which utilizes dual bellows pumps that are activated by means of a common lever actuator. In this dispenser the components of each of the chambers is delivered in a different ratio. The pistons in this dispenser are drawn upwardly by means of a suction force in distinction to the use of piston rods that push a piston and exert a positive pressure on the paste to be dispensed. 
     In the present dispenser various problems with regard to the prior art dispensers are overcome. The pumping mechanism is of the suction type and can dispense essentially equal amounts of substances having different rheologies. The dispenser is more compact and easier to handle and use. In addition, less plastic is needed for each dispenser resulting in an environmental saving. Further, since compact refill cartridges are used, the plastic usage is further decreased. The base and the pumping head are reused with only the cartridges disposed of after the contents have been depleted. 
     The present pump dispenser also has a unique technique for maintaining the two streams of substances being dispensed separate until use. The closure is a slit membrane closure which keeps each stream that is being dispensed separate. There is no cross-contamination of one substance with another. In a preferred embodiment each stream exists through a separate slit opening in the membrane. After dispensing the exterior surface of the membrane, closure can be cleaned if necessary. This can be done by cleaning the exterior surface. 
     This present multi-chamber dispenser solves these many problems. It is an advance in the art of multi-chamber dispensers, and particularly multi-chamber dispensers that pump substances by suction rather than by a direct force on a piston, such as through the use of an arrangement of a piston rod directly acting on a piston. 
     BRIEF SUMMARY OF THE INVENTION 
     The present pump dispenser is comprised of an upper section and a lower section. The upper section and the lower section preferably releasably fit together. The lower section is comprised of at least two tubular chambers which contain the substance to be dispensed. There also is a shroud which encircles the tubular containers and which connects to the upper section. This shroud preferable has apertures along each side wall which function as windows permitting an observation of the fill level of substance in each tubular container. The tubular containers preferably are removable from the shroud and the shroud separable from the upper section, and, as an option, the tubular containers are joined together at the top, bottom, or otherwise along a portion of their longitudinal surface. Additionally, in a preferred mode, the joined tubular containers are keyed to fit into the lower section in a single orientation. Replacement tubular chambers have a piston closing the bottom and a foil or other seal on the upper end. Further, at the lower end of the shroud of the lower section, as a part of the front surface, there is an extended foot portion to provide stability to the lower portion when supported on a surface during dispensing. 
     The upper section contains the pump means, pump actuator means and spout to deliver the substance contained in each of the tubular chambers. The pump means are adjacent to the lower part of the upper section and fit onto the top of each of the tubular containers of the lower section. The pump means preferably are a double valve, self-priming pump means, with a separate pump means fitted onto the top of each tubular chamber. Extending from each pump means is a channel that terminates in a spout, with each channel extending to the spout exit. At the spout exit there is a hinged closure which can be rotatable through a 180 degree arc or a slit membrane closure. 
     A slit membrane closure is a self-closing and self-sealing closure. It maintains the substance in the spout moist since there is minimal air contact. There can be one or more slits extending across both channel openings or separate slits for each channel. There will be a positive cut-off of the product being dispensed. Also, the membrane closure can be designed so that there is no mixing of the substances being dispensed through each channel, The slit can be a single slit traversing each channel or in the alternative there can be a pattern of slits across each channel. Optionally, the same slit can traverse both channels. The slit arrangement and design will be dependent on the substance being dispensed. 
     The pump consists of a two valve suction pump mechanism for each container. The pump mechanism can deliver essentially equal volumes of products from each chamber even if the rheologies of the products differ. It is a characteristic of the suction pump to be affected by the rheology of the substances being pumped. The delivery of equal volumes of such substances is accomplished by using rigid valves and a mechanism to assure the positive closing of each valve. Rigid valves are used in contrast to elastomeric or flexible valves. With elastomeric valves the closing of the valves is not assured and elastomeric materials absorb organics, such as flavor oils, and other components from a substance. This causes the elastomeric to change as to its characteristics with yet additional valve operating problems. In addition, there is needed a mechanism to bias the valve in a closed position. Preferably this is a spring mechanism. This bias mechanism is a part of each of the valves in the pump. The rigid valves have a positive closing with a movement of the full valve to and from a valve seat. 
     The pumping mechanism is comprised of two or more pumping chambers. There is a pumping chamber associated with each tubular container. A lower valve in each pumping chamber is in contact with the substance in a tubular container. The upper valve is located at the top of a pumping chamber and forms the upper surface of the pumping chamber. In a preferred embodiment this valve is a part of the pump piston. Between the lower valve and upper valve is the pumping chamber which is of a volume essentially equivalent to a full dose from a dispensing cycle. In a dispensing cycle the piston, which contains the upper valve, is pushed downwardly with the substance in the pumping chamber dispensed from the pumping chamber to the pump spout. When the activating force is released and the piston moves upwardly, the upper valve closes and the lower valve opens to draw the substances in the tubular containers up into the pumping chamber. As an added feature, the pump is self-priming due to each pump chamber having two valves. 
     The exit of each tubular chamber can be off-set from the longitudinal axis of the tubular chamber in order to minimize the path of the substances from the pumping chambers to the spout. This results in a decreased pumping force to dispense the substances. Further, the lower end of each pump chamber can have an associated knife arrangement to pierce any foil or other covering over the upper ends of the tubular chambers. 
     This multi-chamber dispensing pump solves many problems of past multi-chamber pump dispensers. It is compact, light weight, has a low actuation force has replaceable cartridges, can be used with substances with different rheologies and maintains the substances separate throughout actuation. 
    
    
     BRIEF SUMMARY OF THE DRAWINGS 
     FIG. 1 is a front elevational view of the pump dispenser. 
     FIG. 2 is a side elevational view of the pump dispenser. 
     FIG. 3 is a vertical sectional view of the pump dispenser along line  3 — 3  of FIG.  2 . 
     FIG. 3A is an exploded view in section of the upper valve of the pumping chamber. 
     FIG. 3B is an exploded view of the lower valve of the pumping chamber. 
     FIG. 4 is a vertical sectional view of the pump dispenser along line  4 — 4  of FIG.  1 . 
     FIG. 5 is a horizontal sectional view of the pump dispenser along line  5 — 5  of FIG.  1 . 
     FIG. 6 is a front elevational view of the lower section separated from the upper section. 
     FIG. 7 is a top plan view of the lower section of FIG.  6 . 
     FIG. 8 is a front elevational view of a refill cartridge for the dispenser. 
     FIG. 9 is a view of the spout of the pump dispenser with an overcap having a membrane closure with the dispensing slit extending across each channel. 
     FIG. 10 is a view of the spout of the pump dispenser having a membrane closure with the dispensing slit having dispensing slits depending therefrom. 
     FIG. 11 is a view of the spout of the pump dispenser having a membrane closure with a separate slit for each channel. 
     FIG. 12 is a view of the spout of the pump dispenser having a dispensing membrane closure with more than one separate slit for each channel. 
     FIG. 13 is a view of the spout of the pump dispenser having a dispensing membrane closure with two slits which extend across each channel. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present pump dispenser will be discussed in more detail with reference to the drawings. 
     FIG. 1 shows dispenser  10  which consists of lower section  12  and upper section  14 . The lower section is comprised of shroud  13  and at the bottom of the lower section a foot support  20  which aids in supporting the dispenser during use. The lower section  12  has elongated apertures  22  and  24  on each side. This lower section holds tubular containers  30  and  32  and is removably interconnected with the upper section  14 . The tubular containers hold the substances that are to be dispensed. 
     The upper section  14  is comprised of a shroud  15 , spout  16  and a pump actuator  18 . The pump actuator  18  is connected to each of the pumps and serves to activate each of the pumps simultaneously upon being depressed. The spout  16  extends at an angle from the shroud  15  and on its end is cap  26  which is attached to cap base  27  by hinge  28 . Cap base  27  attaches to spout  16  and rotates the closure through a 180 degree arc. In this way the cap portion  26  of the closure can be rotated so as not to interfere with dispensing the paste. An alternate slit membrane closure is shown in FIGS. 9 to  13  and will be discussed with reference to these figures. 
     FIG. 2 is a side elevational view of the dispenser. This view shows the elongated aperture  22  and tubular chamber  30 . The apertures act as a view windows providing information of the fill status of the tubular containers of the dispenser. The foot support  20  is better shown in this view. The foot support provides stability when the dispenser is activated while on a surface rather than being held while being activated. 
     FIG. 3 shows the internal construction of the dispenser. The upper section  14  holds the pumping mechanism while the lower section  12  holds the substances to be dispensed in tubular chambers  30  and  32 . These tubular chambers slideably interfit into shroud  13 . At the lower end of tubular container  30  is piston  40  and at the lower end of tubular chamber  32  is piston  50 . The tubular chambers are maintained within shroud  13  by bottom wall  21  of the lower section. The tubular containers are connected at the top by bridge piece  31  and at the bottom by bridge piece  33 . 
     The upper section contains the pumping mechanism. This pumping mechanism is a suction type which draws the substances upward from each of the tubular chambers. Each pumping chamber has two valves and it is self-priming. The drawing of the substances from each tubular chamber creates a reduced pressure in each tubular chamber which draws the substances upward into the pumps. This also draws the pistons upwardly. The substances are then discharged in a subsequent operation of the pumps. 
     The upper section contains pumps  42  and  52 . Pump  42  is comprised of pump wall  43  and pump  52  is comprised of pump wall  53 . At the lower end of pump  42  are support spokes  34  and rigid valve  49 . Rigid valve  49  is biased closed by spring  35 . The support spokes support the rigid valve member and in turn are attached to pump wall  43 . Spokes  34  terminate in inlet port  38  of pump  42 . Inlet port  38  will be in contact with the substance in container  30 . Upper rigid valve  45  is supported by support spokes  47 . Spring  23  biases valve  45  in a dosed position. Piston  41  holds the support spokes  47  and moves slideably with regard to pump wall  43 . The upper valve  45  is a part of piston  41  and moves upwardly and downwardly with piston  41 . Pump  42  is connected by intermediate channels  44  and  46  to exit channel  48 . Exit channels  48  and  58  of the dispenser are separated by wall  60 . Wall  60  extends to the exit of the spout to keep the channels separate until the substances are dispensed. 
     Pump  52  has the same structure as pump  42 . Pump  52  has a lower rigid valve  69  which is supported by spokes  36 . Spring  37  biases valve  69  in a closed position. Spokes  36  terminate in inlet port  39 . Inlet port  39  is in contact with the substance in container  32 . Pump wall  53  defines the pump chamber. The upper rigid valve is comprised of valve  55  supported by support spokes  57 . Spring  25  biases valve  55  closed. Piston  51  slideably contacts the pump wall  53 . Upper rigid valve  55  is a part of piston  51  and moves upwardly and downwardly with piston  51 . The pump  52  opens into intermediate channel  54 . Intermediate channel  54  is interconnected to channel  56  which in turn is interconnected to exit channel  58  of the spout. 
     FIG. 3A is an exploded view of the upper valve of each pump chamber and FIG. 3B is an exploded view of the lower valve of each pump chamber. These valves will be described with regard to pump chamber  42  with the understanding that the values of pump chamber  52  have the same structures. The upper valve as shown in FIG. 3A is a part of piston  41 . Piston wall  105  has a series of ridges  106  on an internal surface for attachment onto piston support  74 . Prefereably piston support  74  has mating ridges. On a lower portion of piston wall  105  is the piston seal support  104  which carries cylinder wall seals  100  and  102 . These seals contact cylinder wall  43  and ride along the cylinder wall. Valve  45  contacts valve seat  108  and seals against this valve seat. Valve  45  has upwardly extending guide arms  110 . Spring  35  is attached to valve  45  by stem  112  and enlarged projection  114 . As can be seen, the arms of spring  35  will bias the valve in the closed position. 
     The lower valve is shown in FIG.  3 B. Cylinder wall  43  carries the valve  49  at its lower end. The valve consists of valve seat  120 , rigid valve  49  and spring  35  to bias the valve in the closed position. Spokes  34  support the valve. Spring  35  has arms  126  attached to valve  49  by stem  122  and enlarged projection  124 . Spring arms  126  flex and provide the spring action. The valve seat is mechanically or adhesively attached to pump wall  43 . 
     With further reference to FIG. 3, the pump actuator  18  is connected to piston  41  and piston  51  by means of upper frame support  70 . The upper frame support has guide sections  72  and piston supports  74  and  76 . Piston support  74  has piston  41  mounted thereon and piston support  76  has piston  51  mounted thereon. Each of these pistons except for the valve contained in the piston are of a flexible elastomeric material. The upper frame support  70  in addition has tubular extension  62  which slideably fits over guide pin  64 . Spring  63  biases upper support frame  70  upwardly and actuator  18  in the unactivated rest position. Guide pin  64  is mounted on lower frame support  66 . This lower frame support is attached to the inner surface of shroud  15 . This anchors the lower frame support. Pump walls  43  and  53  project upwardly from the lower frame support and are a part of the lower frame support. Circumferential section  73  of the lower frame support provides for the attachment to the inner wall of shroud  15 . 
     Upon the activation of pump actuator  18  upper frame support  70  moves downward and forces pistons  41  and  51  downward into pump chambers  42  and  52  respectively. Upper valves  45  and  55  open. Lower valves  59  and  69  remain closed. This decreases the volume in each of these pump chambers and forces the substance in pump  42  into channel  44  and then into channel  46  and exit channel  48 . At the same time the substance in pump chamber  52  is forced into channel  54  and then into channel  56  and exit channel  58 . As upper frame support  70  is pushed downwardly by depressing actuator  18 , tubular extension shaft  62  slideably moves over guide pin  64 . Spring  63  is tensioned, biases the upper frame support  70  upwardly and thus actuator  18  upwardly. This also maintains the pumps  42  and  52  in the non-depressed condition as shown in FIG. 3 when the actuation pressure is released. 
     As the upper frame support  70  moves upwardly, piston  41  and piston  51  move upwardly. Upper valves  45  and  55  are closed creating a reduced pressure in pump chambers  52  and  42  respectively. As a result, valve  49  of pump  42  and valve  69  of pump  52  are opened with the substances in tubular chambers  30  and  32  respectively being drawn by suction upward into pump chambers  42  and  52 . The dispenser is then ready for another dispensing cycle. 
     These pumps are self priming pumps. By depressing the actuator several times, the pump chambers when empty are filled with the substances from the tubular chambers. Further depressing of the activator causes the substances to be dispensed with each downward stroke of the activator. As the substances are being dispensed, pistons  40  and  50  are drawn upwardly in each tubular chamber. 
     FIG. 4 is a side elevational view of the dispenser. The closure extension  29  is fully rotatable on spout  26  through 180 degrees. Pump actuator  18  is shown pivoted at axis  19 . This axis  19  is located at the rear of the dispenser. As actuator  18  is depressed, the spout  16  (along with cap  26 ) and the remainder of the upper part of the pump assembly that is a part of upper frame  70  moves downwardly. As has been described, this changes the volume in pump chambers  42  and  52  and provides the force to pump the substances from the tubular chambers to the dispenser exit. 
     FIG. 5 is a cross-sectional view of the dispenser along line  5 — 5  of FIG.  1 . This shows the foot  20 , tubular chambers  30  and  32  and pistons  40  and  50 . Also shown are keys  78  and  79  which permit the cartridge assembly to be inserted in only one orientation. Key  79  cooperates with key slot  82  of projection  80  (see FIG.  6 ). In this way the tubular chambers which are connected longitudinally at common points can only be fitted into shroud  13  in a single orientation. If not in the proper orientation, the tubular chambers will not seat in shroud  13  so that upper portion  12  can be fitted into the shroud  13 . 
     FIG. 6 shows the lower section  12  with shroud  13 . Lower section  12  and upper section  14  are detachable. Projection  80  extends upwardly from the front surface and projection  84  extends upwardly from the rear surface. Projection  80  on the inner surface has a keyway which interfits into key slot  79  of the cartridge. As a result the cartridge only can be inserted in one orientation. In this way there will not be any cross-contamination of the substances in the pump chambers when a new refill cartridge is used. 
     The cartridge refill in the shroud is are shown in FIG.  7 . It is seen that projection  80  carries a keyway  82  which interfits with a key slot  79  on the cartridge. In FIG. 8 there is shown a refill cartridge. This refill cartridge is sealed on the upper end by seals  15  and  16 . Pistons  40  and  50  seal the bottoms of the tubular chambers. 
     FIGS. 9 through 13 describe an alternate embodiment to the closure shown in FIGS. 1 through 4. In FIGS. 9 through 13 there is used a membrane valve at the exit to the spout  16 . This consists of a piece of flexible elastomeric material containing one or more slits which close off the spout. As shown in FIG. 9, this membrane  90  has a slit  91 . In this embodiment, the slit  91  is shown as extending across both channels  48  and  58  of spout  16 . Other designs for the slit are shown in FIGS. 10 through 13. In FIG. 10 there is shown cross slits  92  and  93 . This is a version of the slit opening of FIG. 9 with perpendicularly intersecting slits across each spout channel. In FIG. 11 there are shown separate slits  94  and  95  across each spout channel. FIG. 12 is an embodiment of the slit design of FIG. 10 but with there being a separate slit  96  and  97  for each spout chamber. In FIG. 13 there is shown a slit consisting of two slits  98  and  99  each of which extends across each spout channel and which intersect at the wall  60  dividing the spout channels. 
     The membrane closure can be constructed of essentially any elastomeric material. This includes the different homopolymers and copolymers of butadiene. However, the preferred membrane closures are silicones since they exhibit a rapid return to their initial closed position after a dispensing and further provide for a sharp cut-off of the substances being dispensed. 
     The dispenser shrouds including the foot of shroud  13  are made out of a rigid thermoplastic as are the spout, actuator, upper frame support and lower frame support and activator. Suitable thermoplastics are polyethylene, polypropylene, acrylonitrile-butadiene-styrene or any other easily injection moldable rigid thermoplastic material. 
     The tubular containers can be of any rigid plastic with polyethylene terephthlate, polybretylene terephthalate, polyethylene and polypropylene resins being very useful. The pistons and valves are usually a thermoplastic such as polypropylene of low to high density. The valves also may be fashioned on any of the injection moldable plastic resins such as ethylene vinyl acetate and styrene-butadiene-styrene block copolymers. It is preferable to select valve materials which are resistant to absorbing organic such as flavor oils or other components of the materials to be dispensed in the pumps. Most of the parts are readily made by injection molding 
     The pistons in the refill cartridge can be a rigid type, deformable type or have a reshapeable polymeric foam top surface. The rigid type is usually of a plastic such as polyethylene or polypropylene where the top of the piston does not deform when it contacts another surface. A deformable piston is one that has a shape that conforms with that of a surface which it will contact and due to the surface being deformable will fully fit into that surface. A polymeric foam piston is one which has an upper part that is a polymeric foam such as a polyurethane foam and which changes in shape to conform to the shape of a surface which it contacts. This can be soft to a more rigid foam. The advantage of a foam piston is that when a cartridge is removed there is no substance residue on the mating surface. The lack of a residue results in a clean separation of the cartridge from the pump with no smearing of the substances onto the inner parts of the upper section of the pump. 
     The description of the dispenser discloses the preferred embodiments of the dispenser with various modifications possible and yet be within the concepts of this dispenser. All such modifications are considered to be a part of the present development.