Mechanical intermittent timer flow controller

An intermittent fluid flow controller including a main body that houses an inlet in controlled fluid communication with an outlet, a mechanical timing mechanism including a rotatable member that rotates during an operation of the timing mechanism, and a first valve operated by the rotatable member. The first valve is disposed in the main body such that a rotational movement of the rotatable member actuates the first valve to intermittently permit and restrict a fluid flow between the inlet and the outlet over a pre-selected period of time determined by the operation of the timing mechanism.

FIELD OF INVENTION

The present invention relates generally to the field of water valve timers. More specifically, the present invention is directed to a mechanical intermittent timer flow controller which provides for intermittent on/off cycles during an irrigation application.

BACKGROUND OF INVENTION

There is a recognized need for timer valve assemblies that permit flow of water for certain periods of time. The current examples of such valves typically include a timer, a water inlet and an outlet. A water source, such as a spigot, is connected to the inlet while a hose or other watering device is coupled to the outlet. The valve assembly is controlled by a timing device which will open the valve and keep it open to allow water flow to the outlet. In such a manner, a user simply sets the timer for a pre-determined period of time. The user does not need to return to the valve assembly to shut off the water flow to prevent over-watering.

Various timer mechanisms have been used in the past. For example, an electronic timer has been used. Electronic timers may be analog or digital and may also use electrical power to actuate the on-off valve. Such timers are very accurate, but suffer from several shortcomings. If the electrical power is supplied by a battery, the timer has a limited life. Further, the timer must be constructed to protect the battery from outside elements, thereby increasing the weight of the device and the number of component parts. Alternatively, the electrical power may be supplied through a standard electrical outlet. However, this limits the effective range of the valve as it must be placed in proximity to an electrical outlet in order to function. Also, electrical devices cause some safety concerns due to a risk of electric shock and moisture-related “shorting.”

Another type of timer which has been used is a water-driven mechanical timer. One example of such a timer includes an impeller interposed between the inlet and the outlet of the valve. The impeller is rotated by the water flow. A gearing system is coupled to the impeller to activate the valve after some time period to stop the water flow. The impeller-based timer is self-running and thus does not require an independent power source. However, this type of timer suffers from inaccuracy because the rotational speed of the impeller depends entirely on the rate of water flow which may not be constant from source to source. In addition, if the water flow is of a sufficiently low pressure, the valve may not shut off.

A variety of valve assemblies have used mechanical wind-up timers. These timers typically operate using a spring which is wound up and gradually released such that the valve closes and shuts off water flow when the timer has run out. However, because such timers have a timing mechanism that does not directly couple to the valve assembly, additional torque must be generated by the spring to activate a separate mechanism to open and/or close the valve assembly, and thus the valve assembly is not as efficient. The complexity and size required of the mechanisms in many such prior art designs increase the manufacturing costs.

For certain soil and vegetation types, it is advantageous to water in intermittent increments over a pre-determined length of time. Such a watering scheme can serve to prevent short-term saturation and excess watering by limiting both the timing of a on/off watering cycle and the total length of watering time (e.g., water on for five minutes then off for ten minutes, over a three hour period). It can also help to conserve water by allowing a finite overall watering period and by allowing water from an “on cycle” to be absorbed during an intermittent “off cycle” rather than accumulating on a watering surface where it is more likely to be lost to evaporation and/or runoff. Some complex mechanical timer/valve designs and some electronic timer/valve designs have been used in an attempt to address this need. However, current wholly mechanical (i.e. non-electrical) timer valves do not presently offer an efficient design for intermittent timed watering over a set watering time, and the available electronic intermittent timers suffer from the disadvantages discussed above.

Thus, there is a need for a mechanical timer in which the mechanical components are coupled with the valve assembly to conserve space while providing increased mechanical efficiency. There is a further need for a mechanical timer which is accurate but requires no outside power source. There is also a need for a mechanical timer that includes a less complex assembly and which provides an accurate, efficient intermittent watering feature throughout a pre-determined watering cycle time.

SUMMARY OF THE INVENTION

These needs and others are addressed in embodiments of the present invention, one example of which is a timer-controlled intermittent flow controller for controlling the flow of water.

In one aspect, the present invention is related to a water flow controller for an intermittent watering operation including an inlet in controlled fluid communication with an outlet and a mechanical timing mechanism with a rotatable shaft operably contacting a rotatable cam member such that a rotating of one of the shaft and the cam member translates to rotating of the other. The flow controller also includes a first valve operably connected to the rotatable cam member such that a rotational movement of the cam member actuates the valve to intermittently permit and restrict a water flow between the inlet and the outlet over a pre-selected period of time. The valve may be located along or parallel to a central axis of the water flow controller.

In another aspect, the present invention relates to an intermittent fluid flow controller that includes a main body with an inlet in controlled fluid communication with an outlet and a mechanical timing mechanism including a rotatable member that rotates during an operation of the timing mechanism. The flow controller also includes a first valve operated by the rotatable member and disposed in the main body such that a rotational movement of the rotatable member actuates the first valve to intermittently permit and restrict a fluid flow between the inlet and the outlet over a pre-selected period of time determined by the operation of the timing mechanism.

It is to be understood that both the foregoing brief description and the following detailed description are not limiting but are intended to provide further explanation of the invention claimed. The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the invention.

DETAILED DESCRIPTION

While the present invention is capable of embodiment in various forms, there is shown in the drawings and will hereinafter be described sample embodiments of an intermittent water flow controller with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiments illustrated.

FIG. 1is a perspective view of a mechanical intermittent timing flow controller100of the present invention.FIG. 2shows an exploded view of one embodiment of the mechanical intermittent timing flow controller100. The mechanical timing flow controller100includes a main body102which includes a water inlet104and a water outlet106. The flow controller also includes a dial knob108, which includes an indicator collar110. The internal components and structure of the body102are illustrated inFIGS. 3A-3Bas described below. The internal structures and components of a sample timing mechanism embodiment150are illustrated inFIGS. 6A-6Cbelow. The water inlet104includes a hose coupler112, for attachment to a standard hose bib or sill cock connector. The water outlet106includes a male coupling member114, which includes a threaded exterior for coupling to a hose or other complementarily threaded device. In other embodiments, other types of hose connectors may be used for one or both of the inlet104and the outlet106such as, for example, a quick-connect type of connector.

When the flow controller100is assembled, the dial knob108is installed on the top of the body102. The dial knob108includes a gripping surface118with indentations to facilitate gripping and turning the knob108. In the illustrated embodiment, the indicator collar110includes a series of time-marking indicia122printed in 30-minute increments for aligning with an indicator124located on the surface of the body102. A user may turn the dial knob108, aligning a desired time marking indicia122with the indicator124to set the length of time that the flow controller100will remain in operation. The illustrated embodiment of the flow controller100allows for a continuous time setting or an intermittent time setting. In the flow controller100as shown, the desired time may be selected for continuous watering for up to three hours, or the user may select an intermittent on-off setting wherein, for example, the water is on for five minutes, then off for fifteen minutes over a time period of up to three hours. Those of skill in the art will appreciate that mechanisms for other time periods and other intermittency patterns are possible and within the scope of the present invention. Additionally, other time-setting indicia may be used in other embodiments. For example, the time marking indicia may be marked in different time increments and/or marked on the body102, while the indicator could be placed on the dial knob108.

A body cap148of the flow controller100mounts to the body102with tabs152that engage inner notches (not shown) for the body102. The dial knob108is rotatably attached to the body cap148by pins (not shown) through the indicator collar110that slidingly engage a groove107in the body cap148. Thus, when the flow controller100is assembled, the indicator collar110surrounds the body cap148and slightly overlaps the upper edge of the body102.

The dial knob108houses an assembly that includes a partially rotatable top cap126, a wave-toothed cam member128, a lock-on plate130, a coil spring132, and a spring retainer134. The wave-toothed surface127of the cam member128includes crests136and troughs138(the “wave-toothed” surface is a somewhat rounded adaptation of a crenellated surface wherein the crests correspond to teeth or merlons and the troughs correspond to interdental gaps or crenels). The dial knob108includes a mounting core140around which the cam member128, the lock-on plate130, and the coil spring132are slidingly disposed. The spring retainer134is fixedly mounted to the mounting core140and serves to retain the cam member128, the lock-on plate130, and the coil spring132in the dial knob108. The coil spring132is disposed between the fixed spring retainer134and the lock-on plate130so as to bias the lock-on plate130against the cam member128.

The cam member128is attached to the top cap126and can be rotated between a first and second position relative to the lock-on plate130by twisting the top cap126relative to the dial knob108. The first and second positions correspond, respectively, to an intermittent timing configuration and a “timed on” configuration. The top of the lock-on plate130has a crenellated rim142including low edges144and high edges146. The lower inside surface of the cam member128includes protrusions (not shown) that, in the first position, abut the low edges144, allowing the lock-on plate130to move closer to the cam member128. In the second position, the protrusions (not shown) abut the high edges146, pushing the lock-on plate130against the bias of the coil spring132, and farther away from the cam member128.

A cam follower154is mounted on an optional cam follower coil spring156above the body cap148. The cam follower154is sized, shaped, and positioned to engage the wave-toothed surface127of the cam member128and/or the lower surface of the lock-on plate130. When the lock-on plate130is in the second position, a lower surface portion of the lock-on plate130pushes the cam follower154against the biasing force of the cam follower coil spring156into a “down/open position.” When the top cap126and the lock-on plate130are in this second position, the flow controller100operates continuously without intermittent “off periods” for the amount of time the user selects. In some alternative embodiments, this “timed on” feature may be absent. The portion of the cam follower154engaged with the wave-toothed surface127of the cam member128forces the cam follower154into the down position when engaged with a crest136, and allows the cam follower154to move into an “up/closed position” when engaged with a trough138.

The “down/open” and “up/closed positions of the cam follower154correspond to the interaction of the cam follower154with a stem valve160. The cam follower154is mounted on a plunger stem158of the stem valve160, around which the cam follower coil spring156is mounted. Up and down movement of the cam follower154in response to its engagement with the one or both of the wave toothed surface127of the cam member128and the lock-on place130translates directly into up and down movement of the plunger stem158of the stem valve160. The function of the stem valve160as it relates to the open/on and closed/off configurations of the flow controller100is explained in greater detail below with reference toFIGS. 3A-3B.

The body cap148includes a central aperture162through which the drive shaft164of a timing mechanism150extends to engage the mounting core140of the dial knob108. The body cap148also includes an offset aperture (not shown) through which the plunger stem158extends to engage the cam follower154. The timing mechanism150is a spring-driven wind-up timer of a type known in the art, and can be a different type of timer in alternative embodiments. While the upper and lower plates450,452of the timer are shown by way of orienting the components of the flow controller100inFIG. 2, an example of a timing mechanism150used in the flow controller100is illustrated in more detail inFIGS. 6A-6C. The engagement of the timer drive shaft164with the mounting core140allows the dial knob108to be used to wind up the timer150.

The internal features of the body102are illustrated inFIGS. 3A-3B. The position of the timer150relative to the other internal components of the body102is indicated inFIGS. 3A-3Bby showing in phantom lines a lower plate452of the timer. The following description of operation of the flow controller100assumes a flow of distally directed, pressurized water through the inlet104into an inlet lumen166from, for example, a spigot.FIG. 3Ashows a longitudinal cross-sectional view of the body102of the flow controller100in a closed configuration (i.e., with the cam follower154and the stem158in an “up” position as described above and not allowing water passage from the inlet104to the outlet106). The body102of the flow controller100includes the proximal inlet lumen166, a first valve chamber168, a second valve chamber170, and a distal outlet lumen172. The inlet lumen166is divided from the outlet lumen172by a dividing wall174. A proximal aperture178provides for fluid communication between the inlet lumen166and the first valve chamber168. An intermediate aperture176is disposed between the first valve chamber168and the outlet lumen172. The intermediate aperture176is in controlled fluid communication with the proximal aperture178.

As shown inFIG. 3A, when the flow controller100is in a closed configuration, a diaphragm valve180in the first valve chamber168is biased sealingly against the dividing wall174by a coil spring182. In this “valve closed” configuration, when the diaphragm valve180is biased sealingly against the wall174, it seals the intermediate aperture176and the proximal aperture178from fluid communication with each other. A resilient diaphragm184of the diaphragm valve180separates the inlet lumen166and the outlet lumen172from the first valve chamber168. A portion of the diaphragm184that is disposed just below the proximal aperture178substantially separates the first valve chamber168from the inlet lumen166. This portion of the diaphragm184includes two small holes186in it, permitting fluid communication from the inlet lumen166through the proximal aperture178into the first valve chamber. Specifically, a limited flow of water from the inlet lumen166may pass through the proximal aperture178and the holes186of the diaphragm184into the first valve chamber168. Optionally, a channel (not shown) from the inlet lumen166to the first valve chamber168may provide fluid communication therebetween instead of, or in addition to the fluid communication provided by the holes186in the diaphragm184.

A valve chamber divider188separates the first valve chamber168from the second valve chamber170. The divider188includes a port190that allows fluid communication between the first valve chamber168and the second valve chamber170. Optionally, the first and second valve chambers may be embodied in a single valve chamber.

A distal aperture192extends between the second valve chamber170and the outlet lumen172. When the flow controller100is in a closed configuration, the head194of the stem valve160in the second valve chamber170is biased sealingly against the distal aperture192by a coil spring196such that water in the second valve chamber170is substantially prevented from flowing through the distal aperture192into the outlet lumen172. The plunger stem158of the stem valve160extends through the outlet lumen172and up through the body cap148into the cam follower154as described above.

As shown inFIG. 3A, when the flow controller100is in a closed configuration that prevents water flow from complete passage therethrough, the cam follower154is engaged with a trough138of the wave-toothed cam member128such that the cam follower154and the stem158are in an “up” position. As described above, in this configuration, the head194of the stem valve160is sealingly biased against the distal aperture192by its coil spring196and the diaphragm valve180is sealingly biased against the dividing wall174. This closed configuration of the flow controller100prevents water from the proximal inlet104from flowing to and through the distal outlet106. Thus, in this configuration, water from the inlet lumen166passes only through the aperture178and through the diaphragm holes186into the first valve chamber168. Until the first and second valve chambers168,170are substantially filled, the water flow continues through the port190of the divider188into the second valve chamber170. When the first valve chamber168and the second valve chamber170are filled with water, the resulting static hydraulic pressure in the first valve chamber168supplements the biasing force of the coil spring182, holding the diaphragm valve180sealingly against the dividing wall174, thereby substantially sealing the proximal and intermediate apertures176,178. The space occupied by water when the flow controller100is in a closed configuration is indicated by an arrow-line198.

As shown inFIG. 3B, the flow controller100is in an open configuration when the cam follower154is in an “down” position and is engaged with a crest136of the wave-toothed cam member128. In this open configuration, the plunger stem158of the stem valve160is pushed down, and the valve stem head194moves down to allow water to pass from the second valve chamber170through the distal aperture192to the outlet lumen172. Dynamic hydraulic pressure from the water in the inlet lumen166forces down the diaphragm184, pushing water in the first valve chamber168through the port190in the divider188, the second valve chamber170, out through the distal aperture192to the outlet lumen172, and on out through the outlet106. At the same time, the resulting decrease in static hydraulic pressure within the first valve chamber168allows the dynamic hydraulic pressure from the inlet lumen166to push down the diaphragm valve180against the biasing force of its coil spring182. Thus, when the diaphragm valve180is in a down/open position, water is free to flow from the inlet lumen166through the proximal aperture178, under the wall174, through the intermediate aperture176, then to and through the outlet lumen172. The flow path of the water when the flow controller100is in an open configuration is indicated by arrow-lines200.

In an intermittent timing operation of the flow controller100, the timing mechanism150rotates the dial knob108and the wave-toothed cam member128for a user-selected period of time. As the cam member128rotates, the cam follower154alternately engages crests136and troughs138providing, respectively, open/on and closed/off configurations of the stem valve160and thereby of the entire flow controller100as described above. The spacing of the crests136and troughs138on the wave-toothed cam member128(combined with the rate of rotation of the timer shaft164) determines the periodicity of the intermittent open/on-closed/off cycles of the flow controller100. For example, a long crest136allows for a long dwell time of the stem valve160in an open/on position. In the embodiment illustrated inFIGS. 3A-3B, the troughs138and crests136are sized and spaced to provide for an intermittent cycle of 5 minutes open/on and 15 minutes closed/off. In alternative embodiments, one or both of the open/on and closed/off times may be longer or shorter. The shape of the teeth/waves on the cam member also can be varied in alternative embodiments within the scope of the present invention.

An alternative embodiment of a handle and cam assembly602of a flow controller600of the present invention is shown inFIG. 4. In this embodiment, a plurality of interchangeable cam members202a-202cis provided, offering different crennelation patterns on the cam members202for different intermittent watering times. An alternative embodiment of a knob handle116is shown on the flow controller500. This knob handle116also engages the timer shaft164and the cam members202. In this embodiment, a user selects and installs a cam member202that provides a desired intermittent watering pattern. For example, the cam member202aprovides a watering cycle of on for 5 minutes and off for 7 minutes; the cam member202bprovides a watering cycle of on for 10 minutes and off for 4 minutes; and the cam member202cprovides a watering cycle of on for 12 minutes and off for 2 minutes. In a further alternative embodiment, a cam member202may have an irregularly crennelated camming surface to confer an irregular intermittent watering cycle (e.g., on for 3 minutes, off for 10 minutes, on for 5 minutes, off for 8 minutes, on for 7 minutes, off for 2 minutes, etc.). In the illustrated embodiment, the cam follower structure120is a roller121on an angled tip of the stem158. Any number of irregular cam surface patterns may be used to provide for a desired intermittent timing period.

In another alternative embodiment, two crennelated cam members204,206are provided as part of a knob handle116and cam assembly612of a flow controller610. This embodiment is illustrated inFIGS. 5A-5C. InFIG. 5A, both cam members204,206are shown relative to the knob handle116and the body102including the cam follower120(of the stem valve160(not shown, concealed within the body102)). The inner cam member204is rotatably adjustable relative to the outer cam member206in which it is nested. The inner cam member204includes an inner crenellated surface225with teeth208and gaps209between the teeth208. The outer cam member206includes an outer crenellated surface226with teeth210and gaps211between the teeth210. The nested position of the inner cam member204in the outer cam member206is such that the inner crennelated surface225is annularly positioned inside the outer crennelated surface226. In alternative embodiments, the outer cam member206may be adjustable relative to the inner cam member204, or both cam members204,206may be adjustable relative to one another. Other sample embodiments of handle assemblies with adjustable, annularly arranged cams are shown inFIGS. 7 and 8.

Adjusting the inner cam member204relative to the outer cam member206changes the dwell times in the open/on and closed/off positions of the cam follower120and the stem valve160by altering the net length of the toothed surface (208plus210) and gapped surface (209plus211) of the crenellated surface(s)225,226in contact with the cam follower120. This adjustability provides for the ability to alter the on/off intermittent cycle without changing cam members. Also, by adjusting the cam members204,206relative to each other, a user has a great deal of flexibility in choice of intermittent on/off cycle times. For example, inFIG. 5B, the cam teeth208of the inner cam member204are aligned substantially directly with the cam teeth210of the outer cam member206providing an on/off cycle of on for 5 minutes and off for 12 minutes. InFIG. 5C, the cam teeth208,210of the inner and outer cam members204,206are offset to provide an on/off cycle of on for 7 minutes and off for 8 minutes. This change of cycle time results from the cam follower120contacting a longer net toothed surface (208plus210) and a shorter net gapped surface (209plus211).FIG. 5Dis a cross-sectional detail along line5D-5D inFIG. 5C, and illustrates (as being engaged with the cam follower120) the relative position of the cam teeth208,210at a point where they fully overlap.FIG. 5Eis a cross-sectional detail along line5E-5E inFIG. 5C, and illustrates the relative position of a cam tooth208(as being engaged with the cam follower120) when only the inner cam member204is engaged with the cam follower120and holding it in the down/open position. In a further embodiment, more than two cam members can be provided.

In yet a further alternative embodiment, the application ofFIGS. 5A-5Cmay be combined with the embodiment shown inFIG. 4by providing multiple inner and/or outer cam members that can be arranged in annularly nested fashion to offer users a broad array of intermittent time period choices. In such embodiments, one or both of the outer cam and the inner cam may be interchangeable. In a further alternative embodiment, three or more cam members may be provided. In still another embodiment, the crenellated surface of the cam(s) may interface directly with the stem of the stem valve instead of acting through a cam follower. In yet another embodiment, the cam follower may be a lever with a fulcrum between the cam follower's connection with the stem valve and the cam follower's contact point with the cam(s); in such an embodiment, the on/off cycle relative to cam position could be reversed (with troughs/crenels corresponding to “off” and crests/merlons corresponding to “on”). In yet another alternative embodiment, not shown, the operation of a stem valve may be controlled by up and down movement of a cam member fixedly attached to a single stem valve such as is illustrated in U.S. patent application Ser. No. 10/891,285, which is assigned to L.R. Nelson Corp. of Peoria, Ill., and which is incorporated herein by reference. In such an embodiment, the crennelated surface of cam member could ride over a fixed protrusion, causing the cam member to confer up and down movement to the stem valve. In still another embodiment, not shown, the single valve may be located along or parallel to a central axis of the flow controller.

FIGS. 7 and 8illustrate two alternative embodiments of handle assemblies for a flow controller, each having annularly arranged cams for adjusting timing of a water flow.FIG. 7shows a controller handle assembly700that includes an outer cap702attached to an outer crenellated cam710, and a top adjusting knob704connected by a shaft706to an inner rotatable/adjustable crenellated cam708. The outer cap702is fixed to the outer crenellated cam710, and the inner rotatable/adjustable crenellated cam708is rotatable relative to the outer cap and outer crenellated cam710. A user may alter the relative positions of crenellated camming surfaces of the two cams708,710by twisting the top adjusting knob704to rotate the inner rotatable/adjustable crenellated cam708relative to the outer crenellated cam710. Similar to the manner described for the annularly arranged cam members inFIGS. 5A-5E, the change in relative position between the cams708,710will change the interaction of the overall camming surface with a valve of the timer, thereby changing the intermittent period during a timer/flow controller operation. The cam positions in this and other embodiments can be adjusted such that there is never an “off gap” between the open/on positions of the valve such that the flow controller acts as a “timed on” valve assembly that remains in an open/on position for the user-selected time, without closing/turning off intermittently.

FIG. 8shows a controller knob assembly800with an adjustable outer crenellated cam802. The controller knob assembly800includes an outer cap804that is fixedly attached to an inner crenellated cam member806. The adjustable outer crenellated cam member806is rotatable relative to the outer cap804and inner crenellated cam member806. An adjustment tab808is attached to the adjustable outer crenellated cam802and extends through a slot810in the outer cap804. A user can adjust the adjustable outer crenellated cam802to alter the relative position of its teeth/gaps relative to the teeth/gaps of the inner crenellated cam member806. Similar to the manner described for the annularly arranged cam members inFIGS. 5A-5E, the change in relative position between the cams802,806will change the interaction of the overall camming surface with a valve of the timer, thereby changing the intermittent on/off period during a timer/flow controller operation.

FIGS. 6A,6B, and6C are views of a timing mechanism150which is mounted in the valve body102. The illustrated timing mechanism150includes an escapement. Other embodiments of mechanical timing mechanisms may be used in other embodiments of the present invention. The windup shaft164is rotated by rotating the dial knob108. The timing mechanism150includes two opposite upper and lower plates450,452which are fixed in place by pins454,456and458. The windup shaft164is seated in a socket460which is on the lower plate452. A washer462is attached to the end of the windup shaft164and includes a protruding tab463. The washer462rotates with the windup shaft164and stops the shaft164when the protruding tab463contacts a stop464formed on the lower plate452. In this manner, the windup shaft164may be turned a maximum of one full rotation. The wind-up shaft164is attached to one end of a coil spring466that is held in place on the upper plate450. The other end of the coil spring466is crimped around a tab468extending from the upper plate450.

The upper and lower plates450,452form a gearbox470that provides a controlled resistance against the spring force of the coil spring466in the form of an escapement gear series. The coil spring466is wound up when the wind-up shaft164is turned via the dial knob108. The coil spring466is released on a gradual basis through the escapement action of the gearbox470, thereby turning the wind-up shaft164back to its original position.

The wind-up shaft164has a drive gear472, which is mounted on the side of the upper plate450opposite the spring466. The drive gear472meshes with a first sun gear474, which is mounted on a first shaft476that is held between the upper and lower plates450,452. The first sun gear474is coupled to a first planet gear478that meshes with a second sun gear480, which is mounted on a second shaft482that is held between the upper and lower plates450,452. In turn, the second sun gear480is coupled to a third planet gear484, which meshes with a third sun gear486that is mounted on a third shaft488, which is held between the upper and lower plates450,452. The third sun gear486is coupled to a planet gear490that meshes with a fourth sun gear492, which is mounted on a fourth shaft494that is held between the upper and lower plates450,452. The fourth shaft494also includes a fourth planet gear496which is rotated with the fourth sun gear492. The fourth planet gear496meshes with a fifth sun gear498that is mounted on a fifth shaft500, which is held between the upper and lower plates450,452. The fifth sun gear498is coupled to a sprocket502, which includes a circumferential series of notches504and teeth505.

A rocker arm506is mounted to pivot with a sixth shaft508. One end of the rocker arm506has a pair of pins510,511that rest alternately in a notch504and on a tooth505of the sprocket502. When the sprocket502rotates, the pins510,511are moved alternately between contact with teeth505and notches504, causing the rocker arm506to rockingly pivot back and forth with the sixth shaft508. The opposite end of the rocker arm506includes a pair of gear teeth512, with one on either side of with a flywheel pin514. The pin514extends from a flywheel516which is mounted on a seventh shaft518between the upper and lower plates450,452. The shaft seventh518is attached to one end of a spiral spring520. The other end of the spiral spring520is attached to a securing pin522on the lower plate452. The spiral spring520provides a steady resistance to the movement of the flywheel516. When the rocker arm506rockingly pivots back and forth as a result of force transmitted through the above-described gear series, the pair of gear teeth512bounce the flywheel pin513back and forth between them. This rhyhmically pivots the flywheel516back and forth, acting as a pendulum of the escapement formed by the gearbox470. The steady resistance of the spiral spring520resists the movement of the flywheel516in a manner that keeps its pendulum movement substantially constant.

Thus, the series of gears and the resistance of the spring520permit the coil spring466to rotate the wind-up shaft164slowly to its original position at a constant rotational velocity. The time required to return to the original position is determined by the sun and planet gears and the rotational position that the wind-up shaft164is turned.

The timing mechanism150is relatively simple in operation, allowing decreased manufacturing and assembly costs. Further, the timing mechanism150is installed in-line with the components of the flow controller100to provide a compact internal design of the body102. In alternative embodiments, the timer may be an electronic timer with a motor to turn the cam member, or some other timing mechanism.

It will be apparent to those skilled in the art that various modifications and variations can be made in the illustrated and described embodiments of the present invention without departing from the spirit or scope of the invention. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.