Gravity filtration system

In a gravity filtration system, upper and lower fluid reservoirs may be mated together. Unfiltered fluid may be supplied to the upper reservoir. One or more filters provide fluid communication between the upper and lower fluid reservoirs. Unfiltered fluid passes through the filter into the lower filtered fluid reservoir. The weight of the fluid in the gravity filtration system may be monitored to maximize the fluid flow rate without loss of fluid by supporting the fluid reservoirs on a moveable platform interconnected to a stationary base by a force reactive linkage. Automatic fill components may be provided for automatically actuating a fluid supply valve connected to an unfiltered fluid source. As filtered fluid is withdrawn from the lower reservoir, actuation of the fluid supply valve to an open position permits unfiltered fluid to be supplied to the upper reservoir. Supply of unfiltered fluid to the upper reservoir is stopped upon actuation of the fluid supply valve to the closed position. Upon closure of the fluid supply valve, an equilibrium state in the filtration system will occur after sufficient time has elapsed for the upper fluid reservoir to drain and the filtered fluid level in the lower fluid reservoir no longer rises. Actuation of the fluid supply valve is a function of the weight of the fluid in the filtration system and/or vertical travel of the moveable platform. An indicator responsive to changes in the weight of the fluid in the filtration system may provide an indication of the equilibrium state of the filtered fluid in the lower fluid reservoir.

BACKGROUND

The present invention relates to gravity filtration apparatus and in particular to a gravity water filtration system including an upper unfiltered water reservoir and a lower filtered water reservoir and further including an automatic fill assembly connected to a water supply source. The two reservoirs are at different elevations and are mated in an unsealed manner.

Typically, prior art water filtration devices consist of filter(s) having outer regions in working contact with the upper unfiltered water reservoir and the output core region of the filter is connected to the lower filtered water reservoir. A filter flange seal is installed between the upper reservoir and the filter output core to maintain fluid isolation between the upper and lower water reservoirs. These prior art water filtration devices, however, tend to allow an overflow condition of the filtered water between the mating surfaces of the two reservoirs during an overflow situation. This event may occur when excess supply water is contained in the system resulting in a spillover onto a counter or the like surface and waste of filtered water. Also, unfiltered water may be wasted, which may be equally significant to wasting filtered water during periods of dangerously low and limited water availability.

It is often difficult to operate available water filtration systems at the system's effective capacity. It may be noted that the fastest rate of water filter processing will occur as long as the top unfiltered water reservoir is full to the brim at all times. This condition is the design capacity, where design capacity is the maximum rate of output achieved under ideal conditions. The design capacity requires constant water flow rate through the system with the upper reservoir filled (input) to the brim at all times while the lower reservoir drains (output) at a flow rate equal to the upper reservoir fill rate.

Applicant's pending Non-Provisional patent application Ser. No. 13/942,852 filed Jul. 16, 2013, and Provisional Application No. 61/848,684 filed Jan. 9, 2013, which applications are incorporated herein by reference, disclose a gravity water filtration system enabling the operator to readily maintain optimum effective capacity (or ‘optimum effective’ maximum water weight) by observing the position of an indicator, a scale, or some portion of the system geometry. Once the water system weight is indicated at maximum, the operator may allow the system to achieve a steady state condition (equilibrium), where the filtered water level in the lower water reservoir will be at a maximum level, and the unfiltered water level in upper water reservoir will be at a minimum level. No water should be added to the upper water reservoir while the system water weight is at a maximum as spillover of filtered water will occur. As filtered water is drawn out of the lower reservoir, the indicated mass (water volume) is reduced accordingly, and supply water may be added into the system until the maximum system water weight is again achieved.

Maintaining optimum effective capacity (or maximum water weight) of available water filtration systems is difficult because such systems may contain only supply side upper primary filter(s), or alternatively they may contain upper primary filter(s) used in conjunction (in series) with lower secondary filter(s), all having different diameters, shapes, volumes, and filter saturation conditions thus making visual interpretation of system water weight virtually impossible.

SUMMARY

In a gravity filtration system, upper and lower fluid reservoirs may be mated together. Unfiltered fluid may be supplied to the upper reservoir. One or more filters provide fluid communication between the upper and lower fluid reservoirs. Fluid passes through the filter into the lower fluid reservoir. The weight of the fluid in the gravity filtration system may be monitored to maximize the fluid flow rate without loss of fluid by supporting the fluid reservoirs on a moveable platform interconnected to a stationary base by a force reactive linkage. Automatic fill components may be provided for automatically actuating a fluid supply valve connected to an unfiltered fluid source. As filtered fluid is withdrawn from the lower reservoir, actuation of the fluid supply valve to an open position permits unfiltered fluid to be supplied to the upper reservoir. Supply of unfiltered fluid to the upper reservoir is stopped upon actuation of the fluid supply valve to the closed position. Upon closure of the fluid supply valve, an equilibrium state in the filtration system will occur after sufficient time has elapsed for the upper fluid reservoir to drain and the filtered fluid level in the lower fluid reservoir no longer rises. Actuation of the fluid supply valve is a function of the weight of the fluid in the filtration system and/or vertical travel of the moveable platform. An indicator responsive to changes in the weight of the fluid in the filtration system may provide an indication of the equilibrium state of the filtered fluid in the lower fluid reservoir.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the drawings and description that follows, like parts are marked throughout the specification and drawings with the same reference numerals. The drawing figures are not necessarily to scale. Certain features may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The invention is subject to embodiments of different forms. Specific embodiments directed to gravity water filtration systems are described in detail herein and are shown in the drawings, with the understanding that the disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to the illustrated and described embodiments. The different teachings of the embodiments discussed below may be employed with other fluids or separately or in any suitable combination to produce desired results. The terms “connect,” “engage,” “couple,” “attach,” or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings.

Directing attention now to the figures, a first embodiment of a gravity filtration system generally identified by the reference numeral100is shown inFIG. 1. The filtration system100may include an upper fluid reservoir114and a lower fluid reservoir118mated together in an unsealed manner. In the specific embodiments described herein unfiltered water may be supplied to the upper fluid reservoir114and filtered water is discharged into the lower reservoir118. The water reservoirs114,118are depicted as having a cylindrical shape for illustrative purposes. It is understood however that the water reservoirs114,118are not limited to any particular shape or size. A circumferential flange116fixed about the lower region of the upper reservoir114may be sized and configured to provide a friction fit with the upper outer region of the lower reservoir118when the water reservoirs114,118are mated together as shown inFIG. 1. The friction fit, however, is not water tight and filtered water from the lower reservoir118may overflow onto a supporting surface, such as a counter or table, when excess water is contained in the system.

The upper reservoir114shown inFIG. 1may house a filter119, shown in phantom inFIG. 4. The filter119includes an end sized for engagement in a known manner with a hole in the bottom of the upper reservoir114. Typically, more than one hole may be provided in the bottom of the upper reservoir114in order to accommodate more than one filter119. Any unused holes may be plugged by a plug112to maintain fluid isolation between the upper and lower reservoirs114and118, respectively. Filtered water may be dispensed from the lower reservoir118through a spout117located proximate the bottom region of the lower reservoir118.

The outer surface of the filter119may be exposed to unfiltered water supplied to the upper reservoir114. The inner core region of the filter119is in fluid communication with the lower water reservoir118. Unfiltered water may pass through the filter119and discharged into the lower reservoir118as filtered water suitable for drinking, cooking and other uses.

As noted above, the design capacity of a gravity water filtration system requires constant water flow rate through the system with the upper reservoir filled to the brim at all times while the lower reservoir drains at a flow rate equal to the fill rate. The water filtration system100may be operated at an effective capacity, where the effective capacity is less than design capacity. The effective capacity occurs at a predetermined value of the weight of the “system water.” When operating at its effective capacity, the filtration system100may perform at a significantly high flow rate without loss of water. During periods of inactivity, the filtration system100may achieve steady state or equilibrium.

Referring still toFIG. 1, the water filtration system100includes a base120designed to rest upon a substantially flat surface, such as a counter or table or the like. A generally vertically movable platform122is supported above the base120on a telescoping column comprising a downwardly extending platform telescopic member124fixed to the bottom of the platform122that is in telescopic engagement with an upwardly extending base telescopic member126fixed to the base120.

Continuing withFIG. 1, it will be observed that the platform122moves vertically as a function of the weight of the water in the upper and lower reservoirs114,118of the filtration system100. Platform telescopic member124moves linearly in a constrained manner relative to base telescopic member126as the weight of the water in the filtration system100varies. A fill level indicator134and a graduated scale138may provide a visual indication of the water fill level in the filtration system100. The indicator134may be rotatably connected to a bracket136mounted on the base120. An end of the indicator134may be pivotally connected to the bracket136at shaft139. A coupler link135may connect the indicator arm134to the movable platform122. An upper distal end of the coupler link135may be rotatably connected to the movable platform122at pin137while a lower distal end of the coupler link135may be rotatably connected to the indicator arm134at pin141. The indicator134may move proximate the scale138or the like mounted on the base120to indicate the water fill level in the filtration system100. The indicator134may move proportionally (and/or functionally “f(x),” and/or logrithimically) as a function of the weight of the water in the filtration system100.

An extension spring128may have an upper end connected the platform122and a lower end connected to the fill level indicator134. The extension spring128cooperates with the linkage arrangement between the coupler link135and the fill level indicator134such that as platform122moves down with added water weight, the extension spring128increases in length.

The platform telescopic member124and base telescopic member126may be fabricated of dissimilar materials. For example, telescopic member124may be UHMW and telescopic member126may be steel. In order to prevent separation between the base120and platform122at relatively low water system weights, a stop129may be provided to limit the upward travel of the platform122. The stop129may be secured to the scale138. As the platform122moves upwardly with a reduction in system water weight, the fill level indicator134rotates upwardly about the shaft139. Upon engagement of the fill level indicator134with the stop129, further upward travel of the platform122is stopped. Indicia131may be provided on the scale138to enable an operator to estimate water system weight, although because the system has automatic filling capabilities, such information may be considered extraneous and is merely provided to the operator to indicate that the system is operating normally with pressurized supply water, and being maintained at a regulated, optimum, and relatively constant water system weight.

The automatic fill components of the filtration system100may include a water supply valve140, an actuator link142and a control arm144. The valve140may be secured to the base120and the actuator link142may be secured to the platform122. The control arm144may be connected to the valve140in such a manner that upon engagement of the control arm144with the actuator link142, the valve140is opened permitting unfiltered water to flow through a water supply line146into the upper reservoir114of the filtration system100. The water supply line146may be connected to an outlet port of the valve140at one end and the open distal end thereof secured to the top of the upper reservoir114. One end of the control arm144is fixedly secured to the valve140and the opposite distal end thereof is in contact with the actuator link142. Depending on the rate of withdrawal of water from the lower reservoir118, the flow rate of unfiltered water into the upper reservoir114may vary over a range where the valve140is fully open to fully closed.

The automatic fill components of the filtration system100may be arranged in configurations other than as shown inFIG. 1. For example, if the water supply line145connecting the valve140to the water source is flexible (as opposed to a non-flexible water supply line145), the valve140may be secured to the platform122, and the actuator link142may be secured to the base120. In any event, the relative movement between the base120and the platform122which occurs as a function of the system water weight generally controls the water flow through valve140.

The upper reservoir supply line146of the filtration system100may be at atmospheric pressure and may be generally flexible. The supply line146may be constructed, for example, of polyethylene or some other suitable plastic. However, it may be further noted that supply line146may be rigid, as for example in the shape of an inverted hollow cane and constructed of glass or metal, and may not contact the upper reservoir114. In such instance, the rigid supply line may be threaded to the valve140or otherwise supported by the valve140so that it extends upwardly from the valve140generally vertically and substantially parallel to the stacked upper and lower reservoirs114,118.

As water is drawn out of the lower reservoir118through the spigot117, the weight of the water in the filtration system100will be reduced accordingly. As the platform122moves upward, the control arm144moves upward and opens the water supply valve140thereby supplying unfiltered water to the upper reservoir114. Equilibrium of the filtration system100is established when a balance occurs between water demand and water supply.

A drain hose143may be connected to the platform122. Although the drain hose143is not critical to the function of the filtration system100, it may be optionally installed to prevent water damage to indoor surfaces, such as a counter or the like, in the event of a valve malfunction (valve leaking). The drain hose143may be 1 mil plastic, or flexible waterproof canvas, for example, and collapse flat during normal operation.

The filtration system100may be automatically operated at its design capacity where the fastest rate of processing filtered water occurs when the upper reservoir114is full to the brim at all times. The design capacity is the maximum water output rate under optimum conditions. The filtration system100may be operated at design capacity by maintaining constant water flow through the filtration system100so that the upper reservoir114may be nearly full at all times while the lower reservoir114is nearly empty at all times. The design capacity of the filtration system100may be attained by opening the spigot117and keeping the lower reservoir118generally empty. The control arm144may be adjusted to throttle the water flow through the supply valve140to maintain the upper reservoir114nearly full during the filtering process.

Referring now toFIG. 7, a second embodiment of a gravity filtration system is generally identified by the reference numeral200. As suggested by the common reference numerals, the filtration system200is similar to filtration system100, except for the compression spring250, the control arm244and the manner in which the control arm244is connected to the platform122to open and close the supply valve140. The compression spring250may be positioned between the base120and platform122. Engagement of the upper end of the compression spring250with the bottom of the platform122may be maintained by a spring retention collar252secured to the bottom of the platform122and engagement of the lower end of the compression spring250with the base120may be maintained by a spring retention collar254secured to the base120.

The platform122telescopes relative to the base120at respectively connected telescopic members224and226. The compression spring250biases the platform122upward relative to base120thereby providing a reactive force to the downward movement of the platform122. The valve control arm244may be rotatably secured to the base120at axis1A. The connector link246may be rotatably connected to the control arm244at axis1B, and the opposite end of the connector link246may be rotatably connected to the platform telescopic member224at axis1C. Supply valve140may be secured to the base120as described above with reference to the filtration system100. Different valve styles however, such as valves having vertically orientated seat/piston axes, may be secured in different configurations or orientations for proper operation of the valve and/or manufacturing requirements.

Referring still toFIG. 7, as water is drawn out of the lower reservoir118through the spigot117, the weight of the water in the filtration system200is reduced accordingly. As the reservoirs114,118move upward, the control arm244rotates about axis1A and opens the supply valve140, thereby supplying water to the upper reservoir114. As the weight of the water in the filtration system200increases, the reservoirs114,118move downward until the maximum water weight for the filtration system200is reached and the water supply valve140is closed. Equilibrium of the filtration system200is established when a balance occurs between water demand and water supply.

Referring now toFIGS. 8A and 8B, a third embodiment of a gravity filtration system is generally identified by the reference numeral300. As suggested by the common reference numerals, the filtration system300is similar to filtration system100, except for the location of the water supply valve340, the control arm344and the manner in which the control arm344is actuated to open and close the supply valve340. In the filtration system300, the water supply valve340may be secured to the lid or top341of the upper reservoir114. A stanchion350is secured to the base120at bracket136. The stanchion350extends generally vertically upward from the base120spaced from and substantially parallel to the stacked upper and lower reservoirs114,118. A stanchion extension member352may be secured to the upper end of the stanchion350. Bolts354or the like secure the extension member352to the stanchion350. The control arm344is disposed between and rotatably connected to the extension member352and the supply valve340. The extension member352may be adjustable relative to the stanchion350to align the control arm344with the water supply valve340. The linkage of the control arm344with the water supply valve340may be configured to permit the control arm344to move through a range of rotation so that the water supply valve340is opened when the water mass of the filtration system300drops to approximately ninety percent of optimum or full capacity. The range of rotation of the control arm344may be only a few degrees, shown as angles “α” and “β” inFIGS. 8A and 8B. The angles α and β may be defined by the axis of the distal end of the control arm344and deviate oppositely from a horizontal plane passing through the distal end of the control arm344. A water supply line342may have one end connected to the inlet side of the water supply valve340and the opposite end of the line342connected to a water source. The line342may have a relatively small diameter. For example, the diameter of the line342may be about the same as the water supply line used in drip irrigation or the water supply line for ice makers, and constructed of flexible material such as polyethylene. The water supply line342may be connected to a water source, such as an adjacent faucet or water valve, or to a line leading to an ice maker, for example. The drain line143may be directed toward a sink, or may be plumbed directly to a household drain system.

Referring now toFIGS. 9-11, a fourth embodiment of a gravity filtration system is generally identified by the reference numeral400. As suggested by the common reference numerals, the filtration system400is similar to filtration system300, except for the configuration of the base and the automatic fill components. The base420may include a pair of generally vertically extending legs421. An elongated beam423is fixedly secured to each leg421proximate the upper end thereof and extends at an angle and downward from the leg421forming a generally L-shaped profile. The angle formed by the leg421and the beam423is less than ninety degrees. Each beam423may include a foot pad425at the distal end thereof. The foot pad425may be integrally formed with the beam423or alternatively as a separate component and secured to the beam423. The foot pad425includes a substantially horizontal planar face designed to rest upon a substantially flat surface, such as a counter or table or the like.

A stanchion450may be fixedly secured to the upper ends of the legs421. The legs421, beams423and stanchion450form a stable structure for supporting the platform422above the base420. The stanchion450is fixed to the legs421and extends generally vertically upward from the legs421.

A carriage427may be movably mounted on the stanchion450. The carriage427includes sidewalls429that are secured to the platform422. The sidewalls429may include a substantially horizontal lower portion431extending below and secured to the bottom of the platform422. An intermediate portion433of the sidewalls429extends vertically upward and an upper portion435extends angularly upwardly. An upper roller437and a lower roller439are rotatably secured between the sidewalls429at shafts441and443, respectively. The rollers437and439engage and travel along the stanchion450. The carriage427is constrained by the rollers437and439to travels linearly up and down the stanchion450. The platform422, being fixed to the carriage427, likewise travels linearly relative to the stanchion450.

An extension spring428may have an upper end connected to the stanchion450at a tab451projecting outwardly from the stanchion450. The lower end of the extension spring428may be connected to a transverse plate430disposed between and secured at the opposite ends thereof to the sidewalls429of the carriage427. A shaft453connected to the upper end of the extension spring428extends through a hole in the tab451. A turning nut459may be threaded on a threaded portion of the shaft453. The tension in the extension spring428may be controlled by adjusting the position of the turning nut459on the shaft453in order to establish the spring force (tension) exerted by the extension spring428between the base420and the platform422.

A stanchion extension member452may be secured to the upper end of the stanchion450. Bolts454or the like secure the extension member452to the stanchion450. An adjustable connector455may be threaded to the upper end of the extension member452. The control arm344is connected between the water supply valve340and the connector455in the manner described above with reference to filtration system300.

An optional visual indicator460may be provided to visually indicate the vertical displacement of the platform422. The indicator460may be rotataby secured to the base420at shaft462. A distal portion of the indicator460is supported by a transverse pin464mounted between lobes466extending downward from lower portion431of the sidewalls429of the carriage427. An LED468or other light source may be installed at the distal end of the indicator460to further enhance the visual tool and to also provide a limited amount of night time illumination.

Referring now toFIGS. 12 and 13, a fifth embodiment of a gravity filtration system is generally identified by the reference numeral500. As suggested by the common reference numerals, the filtration system500is similar to filtration system400, except that the filtration system500is configured for manual operation. The filtration system500does not include the automatic fill components that may be automatically actuated to supply water to the upper reservoir114. The filtration system500may include an audio component to signal the operator to add water to the upper reservoir114. The audio component may be a bell501or the like fixed to the distal end503of a leaf support505. The proximal end507of the leaf support505is pivotally connected to the stanchion450at shaft509. The leaf support505movably engages a pin511fixed to a sidewall429of the carriage427. The leaf support505includes a fold or crimp513near its proximal end507. As water is dispensed from the lower reservoir118, the pin511slides along the leaf support505and upon engaging the crimp513causes the leaf support to swing so that the bell501emits an audible signal indicating that water should be added to the upper reservoir114. InFIG. 12, the filtration system500is illustrated in a near full condition andFIG. 13illustrates the filtration system in a near empty condition and depicting the pin511engaging the crimp513in the leaf support505.

Referring now toFIG. 14, a sixth embodiment of a gravity filtration system is generally identified by the reference numeral600. As suggested by the common reference numerals, the filtration system600is similar to filtration systems400and500, except that the filtration system600includes the automatic fill components and a micro switch for actuating a motorized valve at the water supply source. It will be observed that the filtration system600includes the audio components described above to illustrate that both audio and visual features may be included in an automatic fill configuration of a gravity filtration system, if desired. The automatic fill configurations of the filtration systems described herein, however, would not typically include both audio and visual indicators and may not include any position indicators.

The filtration system600may include a micro switch602mounted on the stanchion350. The micro switch602is electrically connected to a main valve at the water source. In the event of a malfunction of the water supply valve340, where excess water may be supplied to the water reservoir114, the platform422engages the micro switch602which actuates the main valve to shut off the supply of water to the water supply valve340.

The input line pressure for the filtration systems described above may be relatively low for the systems to operate normally. For example, the differential pressure between the water supply line145and the atmosphere may be about one pound per square inch (1 psi), thus enabling an operator to use rain barrels or the like as a water source, where the water level within such barrels is about a foot or so above the upper reservoir114.

While various embodiments of a gravity water filtration system have been shown and described herein, other and further embodiments may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims which follow.