Abstract:
An adjustable-volume liquid dispenser is disclosed. In one embodiment, an adjustable-volume liquid dispenser includes a spout and a plunger secured to the spout. The dispenser further includes a plunger lock moveable lengthwise along the plunger. The plunger lock is securable to the plunger at a plurality of positions on the plunger to adjust a volume of liquid to be dispensed. The dispenser also includes a spring in contact with the plunger. In addition, the dispenser includes a chamber comprising an interior for containing liquid. The plunger is slidably arranged with the chamber. A portion of the plunger is disposed within the chamber. Moreover, the dispenser includes a chamber cap secured to the chamber, and a valve disposed within the chamber. The dispenser also includes a shaft secured to the chamber.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the field of liquid dispensers and more specifically to liquid dispensers that dispense liquids in a range of specific volumes. 
     2. Background of the Invention 
     Liquid dispensers are widely used for a variety of applications such as dispensing medications. Conventional liquid dispensers for medications include syringes. Drawbacks to syringes include possible application of improper doses. For instance, a care-giver or the patient may apply an improper dose to the patient. An overdose of the medication may cause unwanted side effects, and an insufficient dose may not attain the desired effect. Additional drawbacks include inability of conventional syringes to be attached to liquid containers. Further drawbacks may include the need for visual acuity, manual dexterity, and an understanding of the importance of accurate dosing by the applier of the dose. Liquid dispensers with spouts have been developed for attachment to liquid containers. However, drawbacks to typical dispensers with spouts also include improper dosing to patients. 
     Consequently, there is a need for an improved liquid dispenser for applying proper doses. A further need includes an improved liquid dispenser that dispenses pre-set volumes of liquid. 
     BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS 
     These and other needs in the art are addressed in one embodiment by an adjustable-volume liquid dispenser that includes a spout and a plunger secured to the spout. The dispenser further includes a plunger lock moveable lengthwise along the plunger. The plunger lock is securable to the plunger at a plurality of positions on the plunger to adjust a volume of liquid to be dispensed. The dispenser also includes a spring in contact with the plunger. In addition, the dispenser includes a chamber comprising an interior for containing liquid. The plunger is slidably arranged with the chamber. A portion of the plunger is disposed within the chamber. Moreover, the dispenser includes a chamber cap secured to the chamber, and a valve disposed within the chamber. The dispenser also includes a shaft secured to the chamber. 
     In another embodiment, these and other needs in the art are addressed by an adjustable-volume liquid dispenser. The dispenser includes a spout and a plunger secured to the spout. The dispenser also includes a spacer ring disposed on the plunger. In addition, the dispenser includes a spring in contact with the plunger. Moreover, the dispenser includes a chamber comprising an interior for containing liquid. The plunger is slidably arranged with the chamber. A portion of the plunger is disposed within the chamber. The dispenser further includes a chamber cap secured to the chamber, and a valve disposed within the chamber. The dispenser also includes a shaft secured to the chamber. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which: 
         FIG. 1  illustrates a perspective view of an adjustable-volume liquid dispenser; 
         FIG. 2  illustrates a side view of an adjustable-volume liquid dispenser with a plunger having grooves; and 
         FIG. 3  illustrates a side view of the adjustable-volume liquid dispenser of  FIG. 2  with a depressed spout; 
         FIG. 4  illustrates a side view of an adjustable-volume liquid dispenser secured to a liquid container; 
         FIG. 5  illustrates a ball valve; 
         FIG. 6  illustrates a side view of a plunger and plunger lock; 
         FIG. 7  illustrates a side view of a plunger and plunger lock; 
         FIG. 8  illustrates a top view of a plunger lock with tabs; 
         FIG. 9  illustrates a top cross sectional view of a plunger with grooves and groove indentions; 
         FIG. 10  illustrates a top view of a plunger with grooves; and 
         FIG. 11  illustrates a side view of an adjustable-volume liquid dispenser with spacer rings. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  illustrates an adjustable-volume liquid dispenser  5  that includes spout  10 , plunger  15 , spring  20 , chamber cap  30 , chamber  35 , and shaft  45 . In an embodiment, adjustable-volume liquid dispenser  5  is suitable for dispensing set volumes of liquid. The liquid may be any desired liquid. Without limitation, examples of suitable liquids include medications, chemicals, water, soap, lotion, food products, and the like. In an embodiment, the liquid is a medication. The liquids may have any suitable compositions and viscosities for use with adjustable-volume liquid dispenser  5 . Without limitation, adjustable-volume liquid dispenser  5  allows repeatable, fixed volumes of liquid to be dispensed. 
     As illustrated in  FIG. 1  spout  10  may include any spout suitable for dispensing a liquid and for attaching to plunger  15 . It is to be understood that spout  10  is not limited to the configuration shown in  FIG. 1  but instead may include any configuration suitable for dispensing a liquid and for attaching to plunger  15 . In an embodiment, spout  10  has at least one pathway (not illustrated) by which the liquid passes from plunger  15  through spout  10 . In the embodiment illustrated in  FIG. 1 , spout  10  has dispensing end  130  through which liquid may exit spout  10 . Spout  10  may be attached to plunger  15  by any suitable method. For instance spout  10  may be attached to plunger  15  by press-fit, adhesive, threaded fastening, and the like. Plunger  15  may have any configuration suitable for allowing plunger  15  to be pushed into chamber  35  to expel liquid from chamber  35 . In the embodiment as illustrated in  FIG. 2 , plunger  15  is a shaft with at least one orifice (not illustrated) that allows liquid to pass from chamber  35  through plunger  15  to spout  10 . In an embodiment as illustrated in  FIG. 2 , plunger  15  extends into chamber  35  through chamber cap  30  and collar  55 . It is to be understood that chamber  35  is illustrated in  FIG. 2  in a cross-sectional view for illustration purposes only. Chamber cap  30  is secured to top  160  of chamber  35 . Chamber cap  30  may be secured to chamber  35  by any suitable means such as by press-fit, threaded fastening, and the like. As illustrated in  FIG. 2 , collar  55  has an orifice  200  that extends through collar  55  with plunger  15  passing through orifice  200 . Orifice  200  has a diameter suitable for allowing plunger  15  to pass through collar  55  but also has a sufficient diameter to prevent any unwanted lateral movement of plunger  15 . In some embodiments, orifice  200  has a diameter suitable for maintaining movement of plunger  15  in a direction parallel to sides  165  of chamber  35 . Collar  55  may have any suitable configuration and diameter to prevent collar  55  from moving into interior  135 . For instance, in an embodiment as illustrated in  FIG. 2 , collar  55  has collar neck  70  and collar base  125 . In some embodiments, collar neck  70  may facilitate prevention of any unwanted lateral movement of plunger  15  and may also control the distance plunger  15  may be displaced, which may control the amount of liquid dispensed. In an embodiment, collar neck  70  has a configuration suitable for interfacing with chamber cap  30  with at least a portion of collar neck  70  disposed within chamber  35 . In an embodiment as illustrated in  FIG. 2 , chamber cap  30  is secured to chamber  35  with a portion of collar neck  70  extending through chamber cap opening  170  and out of chamber  35 . Chamber cap  30  prevents movement of collar  55  out of chamber  35 . In addition, collar base  125  has a diameter sufficient to prevent collar  55  from moving into interior  135 . In some embodiments as illustrated in  FIG. 2 , chamber  35  has collar portion  175  with a diameter greater than that of interior  135 . Collar base  125  has a diameter sufficient for positioning in collar portion  175  but has a diameter sufficiently larger than the diameter of interior  135  to prevent movement of collar  55  into interior  135 . In alternative embodiments (not illustrated), collar  55  and chamber cap  30  are not separate components, but chamber cap  30  is an integral component of collar  55 . 
     As further illustrated in  FIG. 2 , plunger  15  has plunger base  65  disposed on the end of plunger  15  distal to spout  10  with plunger base  65  disposed in interior  135  of chamber  35 . Plunger base  65  has any design suitable to substantially prevent liquid in chamber  35  from passing between exterior surface  140  of plunger base  65  and interior surface  145  of chamber  35 . In an embodiment, plunger base  65  has an orifice (not illustrated) through which liquid may pass from chamber  35  to the pathway of plunger  15 . 
       FIG. 1  illustrates an embodiment in which adjustable-volume liquid dispenser  5  has spring  20  disposed about the exterior of plunger  15  between spout  10  and chamber cap  30 . Without being limited by theory, spring  20  disposed outside of chamber  35  may prevent direct contact of spring  20  with the liquid. Spring  20  may be suitably positioned on plunger  15  to allow plunger  15  to return to a desired extended position after a depressing force is removed from spout  10 . For instance,  FIG. 2  illustrates an embodiment in which plunger  15  is in a non-depressed position, and  FIG. 3  illustrates an embodiment in which plunger  15  has been depressed with compression of spring  20 . Spring  20  may include any spring suitable for use with adjustable-volume liquid dispenser  5  and for returning plunger  15  to a desired extended position. In some embodiments, spring  20  is a helical spring. Spring  20  may also be composed of any material suitable for a desired use. In some embodiments, spring  20  is selected based upon a desired material composition of spring  20  (e.g., rust-resistant), desired mechanical properties (e.g., a desired stiffness), and/or properties of the liquid (e.g., viscosity of the liquid). In an embodiment as illustrated in  FIG. 1 , spring  20  has ends  150 ,  155  with end  150  proximate to spout  10  and end  155  proximate to chamber  35 . In alterative embodiments (not illustrated), spring  20  may be disposed inside chamber  35 . In such an alternative embodiment, spring  20  is disposed between plunger base  65  and valve  40  and may force plunger  15  up through chamber  35  when spring  20  de-compresses after liquid has been dispensed, and force is removed from plunger  15 . Further, in such alternative embodiments, spring  20  may be composed of any material that is non-reactive to the liquid. 
     As illustrated in  FIGS. 1 and 2 , chamber  35  may have any size suitable for a desired amount of liquid to be contained. Chamber  35  may be composed of any material suitable for use with a desired liquid. For instance, chamber  35  may be glass, plastic, or the like. In some embodiments, chamber  35  includes chamber ledge  50 . Chamber ledge  50  has a sufficient length to facilitate attachment of adjustable-volume liquid dispenser  5  to a liquid container. For instance, in an embodiment as illustrated in  FIG. 4 , liquid container cap  115  with liquid container cap orifice  180  is attached to liquid container  120 . It is to be understood that liquid container cap  115  and liquid container  120  are shown in cross-sectional view for illustration purposes only. Liquid container cap  115  may secure adjustable-volume liquid dispenser  5  to liquid container  120 . Liquid container cap  115  is removeably attached to liquid container  120  and may be attached to liquid container  120  by any suitable means. Chamber ledge  50  facilitates the attachment of adjustable-volume liquid dispenser  5  to liquid container  120 . For instance, chamber ledge  50  prevents unwanted movement of chamber  35  through liquid container cap orifice  180  and out of liquid container  120 . In an embodiment as illustrated in  FIG. 4 , chamber ledge  50  may have a diameter greater than that of container opening  185  to allow adjustable-volume liquid dispenser  5  to be disposed upon container opening  185  with liquid container cap  115  securing adjustable-volume liquid dispenser  5  to liquid container  120 . In alternative embodiments (not illustrated), adjustable-volume liquid dispenser  5  does not have chamber ledge  50 . In some alternative embodiments (not illustrated), adjustable-volume liquid dispenser  5  includes a substantially rigid cap or an elastic cap instead of chamber ledge  50 , with the cap disposed at a location on the exterior of adjustable-volume liquid dispenser  5  between chamber cap  30  and shaft  45 . In other alternative embodiments (not illustrated), adjustable-volume liquid dispenser  5  may be secured to liquid container  5  by adhesion, threading, by adhesion or threading into a cap with the cap adhered or threaded into container opening  185 , or any other suitable method. In such other alternative embodiments, adjustable-volume liquid dispenser  5  may or may not include chamber ledge  50 . 
     As illustrated in  FIGS. 1-4 , adjustable-volume liquid dispenser  5  also includes shaft  45 . Shaft  45  is secured to chamber  35  distal to spout  10 . As illustrated in  FIG. 4 , shaft  45  extends into liquid container  120 . Shaft  45  may have any diameter and/or length sufficient to allow liquid to be drawn into chamber  35 . Shaft  45  may be secured to chamber  35  by any suitable means. 
     In an embodiment of the operation of adjustable-volume liquid dispenser  5  as illustrated in  FIGS. 1-4 , chamber  35  of adjustable-volume liquid dispenser  5  is placed within liquid container  120 , which contains a desired liquid. Shaft  45  is sufficiently submersed in the liquid to allow liquid to be drawn into chamber  35 . Liquid container cap  115  is attached to liquid container  120  to secure adjustable-volume liquid dispenser  5  to liquid container  120 . In some embodiments, spout  10  is passed through liquid container cap orifice  180  when attaching liquid container cap  115  to liquid container  120 . In other embodiments, spout  10  is removeably attached to plunger  15  and liquid container cap  115  is passed over plunger  15  with spout  10  removed. Chamber  35  has a valve  40  that controls the flow of liquid into and out of chamber  35  from liquid container  120 . Liquid may be drawn into chamber  35  by applying a force to spout  10  to depress plunger  15  into chamber  35  and removing the force to allow spring  20  to de-compress and return plunger  15  to about its original position. Valve  40  may be any valve suitable for use with adjustable-volume liquid dispenser  5 . In an embodiment, valve  40  is a one-way flow valve. For instance, valve  40  may be a ball valve. In an embodiment as illustrated in  FIGS. 2-4 , valve  40  is a ball valve.  FIG. 5  illustrates an embodiment in which valve  40  is a ball valve including ball  75  and cage  80 . Cage  80  includes any suitable configuration for disposition within chamber  35  in a manner to prevent ball  75  from entering interior  135 . Ball  75  is disposed within cage  80  and has a greater diameter than that of shaft  45 . Valve  40  may be secured in chamber  35  by any suitable means such as by press-fit. In operation, when plunger  15  is not depressed, liquid and/or air in liquid container  120  cannot enter chamber  35  because ball  75  is held in place over shaft  45  by gravity. When a force is applied to adjustable-volume liquid dispenser  5  and plunger  15  is depressed, downward pressure is applied to ball  75 , which further facilitates holding ball  75  is place over shaft  45  and preventing liquid and/or air from entering chamber  35  from liquid container  120 .  FIG. 3  illustrates an embodiment of depressed plunger  15  with compressed spring  20 . In an embodiment in which an upward force is applied to plunger  15  (e.g., by spring  20 ) and plunger  15  is pulled back through chamber  35 , a vacuum is created in interior  135 , and ball  75  moves out of place over shaft  45  to allow liquid to flow into chamber  35  around ball  75 . The vacuum created by the movement of plunger  15  away from valve  40  draws liquid into interior  135 . It is to be understood that cage  80  prevents movement of ball  75  into interior  135 . When upward movement of plunger  15  through chamber  35  stops, ball  75  settles back in place over shaft  45  and prevents further liquid and/or air from entering chamber  35  and also prevents liquid from flowing back out of chamber  35  into liquid container  120 . It is to be understood that de-compression of spring  20  provides the upward force to plunger  15  that provides the upward movement of plunger  15  through chamber  35  and away from valve  40 . It is to be understood that depression of plunger  15  causes plunger base  65  to pass down through chamber  35  in the direction of valve  40 , which increases pressure within interior  135  and forces liquid within interior  135  to flow through the orifice of plunger base  65  to the pathway of plunger  15  and then through the pathway of spout  10  and out of spout  10  via dispensing end  130 . 
     The maximum amount of liquid to be dispensed from adjustable-volume liquid dispenser  5  is pre-set. For instance, in an embodiment as illustrated in  FIGS. 1-4 , plunger lock  60  and plunger  15  having grooves  25  allow the amount of liquid dispensed in one depression to be pre-set. Grooves  25  may have any configuration, depth, and length suitable for locking plunger lock  60 .  FIG. 6  illustrates an embodiment of plunger  15  in which plunger lock  60  is set to a desired position, and  FIG. 7  illustrates an embodiment of plunger  15  in which plunger lock  60  not set to a desired position. As shown, plunger  15  has a series of grooves  25  with groove indentions  95  notched in the exterior surface of plunger  15 . The groove indentions  95  are placed at lengthwise positions on plunger  15  that represent a corresponding amount of liquid that may be contained within interior  135  and dispensed through spout  10 . Without limitation and for example, each lengthwise position of groove indentions  95  on plunger  15  may represent a one milliliter amount of liquid to be dispensed. Therefore, securing plunger lock  60  at position  190  in such an example may dispense five milliliters of liquid. It is to be understood that each lengthwise position may have any suitable number of groove indentions  95 . For instance,  FIG. 9  illustrates a cross sectional top view of an embodiment of plunger  15  in which a position on plunger  15  has four grooves  25  and four corresponding groove indentions  95 . Plunger lock  60  may be secured at each lengthwise position on plunger  15  by tabs  90 . In an embodiment, plunger lock  60  has a number of tabs  90  (e.g., four) that corresponds to the number of grooves  25 . For instance, in the embodiments as illustrated in  FIG. 6-10 , plunger lock  60  may be moved lengthwise along plunger  15  from the position illustrated in  FIG. 7  to the lengthwise position illustrated in  FIG. 6 . Grooves  25  extend lengthwise along plunger  15 .  FIG. 10  illustrates a top view of plunger  15  having grooves  25  running lengthwise along plunger  15 . Tabs  90  are suitably configured for disposition within grooves  25 . It is to be understood that plunger  15  passes through plunger lock opening  100  as plunger lock  60  is moved lengthwise along plunger  15  with each tab  90  disposed within a corresponding groove  25 . When plunger lock  60  is at a lengthwise position of groove indentions  95  representing a desired amount of liquid to be expelled, plunger lock  60  is twisted to the side to move tabs  90  sufficiently into the corresponding groove indention  95  to lock plunger lock  60  in place and prevent further lengthwise movement until plunger lock  60  is twisted to move tabs  90  out of groove indentions  95 . Therefore, when spring  20  de-compresses and pushes plunger  15  out of chamber  35 , plunger lock  60  is locked in place and stops the movement of plunger  15  out of chamber  35  when plunger lock  60  contacts collar  55 . The tension of spring  20  prevents downward movement of plunger  15  until a sufficient force is applied to plunger  15 . In an embodiment in which a total amount of liquid desired to be expelled through spout  10  is an amount larger than chamber  35  may hold, plunger lock  60  may be locked at a suitable lengthwise position on plunger  15  to minimize the amount of compressions of plunger  15  that are needed to obtain the desired liquid amount to be dispensed (e.g., the desired dosage amount). For example and without limitation, plunger  15  has groove indentions  95  at five lengthwise positions with each position representing a milliliter to be dispensed. A desired dosage of the liquid (e.g., medicine) is eight milliliters. Because in such an example chamber  35  may only dispense five milliliters total, plunger lock  60  may be locked at a position representing a four milliliter dosage, which may provide the desired amount of eight milliliters by two depressions of plunger  15 . 
     In alternative embodiments, the amount of liquid dispensed by adjustable-volume liquid dispenser  5  is not set by plunger lock  60  and groove indentions  95 . For instance in alternative embodiments as illustrated in  FIG. 11 , spacer rings  85  are used to set the desired amount of liquid to be dispensed. Spacer rings  85  are placed on plunger  15  and supported by plunger base  65  to limit the distance at which plunger  15  may travel when dispensing the liquid. Spacer rings  85  may be of the same or different sizes. In such embodiments, each spacer ring  85  represents an amount of liquid to be dispensed. Therefore, to dispense a desired amount of liquid, the corresponding amount of spacer rings  85  are placed on plunger  15 . Spacer rings  85  may be placed on plunger  15  by any suitable method. In an embodiment, spacer rings  85  contain an orifice (not illustrated) suitable for allowing plunger  15  to pass therethrough but not allowing plunger base  65  to pass therethrough, and each spacer ring  85  may be slid onto plunger  15  to plunger base  65 . Spacer rings  85  are not limited to a ring configuration but may instead have any suitable configuration. In an embodiment in which a total amount of liquid desired to be dispensed through spout  10  is an amount larger than chamber  35  may hold, a suitable number of spacer rings  85  may be used to minimize the amount of compressions of plunger  15  that are needed to obtain the desired liquid amount (e.g., the desired dosage amount). In alternative embodiments (not illustrated), spacer rings  85  may be disposed on plunger  15  outside of chamber  35 . In such alternative embodiments, spacer rings  85  may be disposed at any suitable location on plunger  15  to provide the known amount of dispensed liquid. 
     In alternative embodiments (not illustrated), plunger lock  60  is placed on plunger  15  outside of chamber  35  and above chamber cap  30  and locked into groove indentions  95 . In such an alternative embodiment, the downward movement of plunger  15  is stopped when plunger lock  60  contacts chamber cap  30 , collar neck  70 , and/or any other suitable stop. 
     In some alterative embodiments (not illustrated), adjustable-volume liquid dispenser  5  includes a counter. The counter may be any device suitable for use with adjustable-volume liquid dispenser  5  and capable of tracking the amount of liquid dispensed, the amount of depressions of plunger  15 , and/or a log of when liquid was dispensed. The counter may be located at any suitable location on adjustable-volume liquid dispenser  5 . For instance, the counter may be located in chamber cap  30 . The counter may be mechanical, electrical, and the like. In some embodiments, for each depression of plunger  15 , the counter is activated. In such embodiments, the counter is electrical and in some alternative embodiments may be powered by a solar panel. In an embodiment, the counter is a mechanical counter that may be activated when plunger  15  is depressed. The results of the activation may be visibly displayed on adjustable-volume liquid dispenser  5  or may be disposed within chamber cap  30 . In an embodiment, the counter is removeably attached to chamber cap  30 . In such an embodiment, the counter may be a mechanical counter, and depression of plunger  15  may physically activate the counter. 
     In other alternative embodiments (not illustrated), adjustable-volume liquid dispenser  5  includes a lock. The lock may include any lock suitable for preventing unwanted depression of plunger  15 . In one embodiment, the lock is a slot within chamber cap  30  that may be twisted to lock plunger  15  in place. In another embodiment, the lock includes a rod that is disposed under spout  10 . The lock may swivel at its base and may be disengaged when dispensing liquid. In other embodiments (not illustrated), the lock includes a locking mechanism having a rod or similar configuration. The locking mechanism is attached to a portion of spring  20  and extends lengthwise along plunger  15 . As plunger  15  is depressed, the locking mechanism may substantially prevent compression of spring  20 . In other embodiments (not illustrated), the locking mechanism may extend from about chamber cap  30  to about spout  10  and may be sufficiently disposed to prevent depression of plunger  15 . For instance, a force applied to spout  10  may cause spout  10  to contact the locking mechanism, which prevents depression of plunger  15  as the opposite end of the locking mechanism contacts chamber cap  30 . In an alternative embodiment, a cover may be used to plug dispensing end  130  and prevent unwanted dispensing of liquid through spout  10 . The cover may be attached to spout  10  by a tether or any other suitable method. 
     Without limitation, setting the distance that plunger  15  extends into chamber  35  controls the amount of liquid that is dispensed out of spout  10 . Therefore, the exact amount of liquid dispensed may be controlled. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims.