Patent Grant
8371474
The present invention generally relates to a fluid dispenser.
Users of public restroom facilities often desire that all of the fixtures in the restroom operate automatically without being touched by the user's hands. This desire is generally due to the increased user awareness of the degree to which germs and bacteria may be transmitted from one person to another in a public restroom environment. As a result, many public restrooms are being transitioned to “hands-free” or “no-touch” restrooms, where all of the fixtures, including toilet and urinal units, hand washing faucets, soap dispensers, towel dispensers and door opening mechanisms, are automatic and operate without being touched by a user. It is believed by many users that hands-free or no-touch public restroom facilities reduces the opportunity for transmission of viruses and bacteria which may result from contact with fixtures in a public restroom.
In office buildings and other similar upscale buildings, the building owner or manager many times wants to offer upscale public restroom facilities to match the buildings décor. One way the building owner or manager can provide an upscale public restroom is to provide in-counter soap dispensers, rather than wall mounted units or on-counter dispensers. In-counter soap dispensers generally have a dispensing nozzle above the counter. Typically, in-counter soap dispensers have a reservoir, which holds the soap, and pump to move the soap from the reservoir to the nozzle. The reservoir and pump are generally mounted underneath the counter. In-counter soap dispensers are known in the art. See, for example, U.S. Pat. Nos. 6,142,342, 6,467,651 and U.S. Patent Application Publication US200910166381 A1. These dispensers deliver an essentially uniform amount of soap on each attenuation of the pump located in the dispenser.
Foam soaps in recent years are gaining in popularity. Generally, foam soaps are stored in a reservoir as a liquid until the time of dispensing. At the time of dispensing, a foam pump pumps the liquid from the reservoir and the pump converts the liquid to foam. Foam soaps tend to be much easier to spread than a corresponding liquid soaps. In addition, foam soaps result in less waste of the soap due to splashing or run-off the users hand since foam soaps typically have much higher surface tension than liquid soaps. Generally, foam soaps give the user a perception of having more soap available to wash their hands than an equivalent weight of a liquid soap. That is, a sufficient amount of a liquid soap to wash a users hand may give the user a perception that there is an insufficient amount of soap to complete the hand washing event. Many times, the user will seek one or more additional doses of liquid soap to complete the hand washing event, if the user perceives the amount of soap dispensed is insufficient to complete the hand washing event. As a result, dispensers which dispense foam soaps tend to provide more hand washings, on a liquid volume basis of the soap in a reservoir, as compared to dispensers which dispense liquid soaps.
In-counter foam soap dispensers are generally of two types. One is a pressurized system which generates the foam at the nozzle. A second type is a non-pressurized system. Pressurized systems are expensive to install and maintain. Non-pressurized systems typically generate the foam under the counter and send the foam to an outlet of the nozzle via a tube. A certain amount of the foam soap remains in the tube until the next use. However, foams tend to collapse overtime and return to a liquid form. This process is called liquefaction. When liquefaction of the foam soap occurs, the dispenser may not dispense a sufficient quantity of the foam soap to effectively clean the hands of the user. Non-pressurized systems have the advantage of a lower initial cost and a lower maintenance cost.
One way to deal with liquefaction is to dispense more foam soap than is needed to clean the user's hands. However, providing too much soap to the user requires the user to use more water to effectively remove the soap from the user's hands. This can result in a waste of water and soap. Wasting water and soap on each hand washing event can result in an increase cost to the building owner in building operation.
Another issue in the art is fluid dispensers which have dispensing tubes which are relatively long may experience fluid loss in the dispensing tube during period of non-use. This can be caused by many different factors, including, for example, evaporation of the fluid, leaking of the fluid from the dispensing tube among other reasons. As a result, a dispenser having a delivery tube may not dispense a sufficient amount of a fluid, in particular a hand cleaning fluid to effectively clean a user's hands.
There is a need in the art for a non-pressurized hands-free foam soap dispenser that effectively will dispense a sufficient amount of foam soap, even if the liquefaction or collapse of the foam soap occurs between uses of the dispenser. In addition there is a need in the art for a fluid dispenser which will always provide a user with sufficient fluid to clean a user's hand during a hand washing event.
Generally stated, the present invention provides an easy to maintain fluid dispenser that will always deliver a sufficient amount of fluid, even if the dispenser has been unused for an extended period of time.
In one embodiment, the present invention provides a fluid dispenser. The fluid dispenser has a reservoir for holding a fluid; a pump having an inlet and an outlet and the pump draws the fluid from the reservoir through the inlet; a dispensing tube directly or indirectly connected to the outlet of the pump; a nozzle; a motor; an attenuator in communication with the motor; a processor in communication with the motor; and a sensor to detect the presence of a user and the sensor is in communication with the processor. The nozzle is adapted to receive the dispensing tube and dispense the fluid to a user. Activating the pump is the attenuator, which is driven by the motor. The processor is configured to determine a time interval between dispensing cycles and to activate the motor for one or more cycles, based on the time interval between dispensing cycles. When the sensor detects the presence of a user, the sensor provides an input to the processor and the processor determines the time period between dispensing cycles and provides an input to the motor to activate for one or more cycles.
In another embodiment of the present invention, the processor of the dispenser activates the motor for a single cycle, if the time interval between dispensing cycles is less than a pre-set time period, or for multiple cycles, if the time interval between dispensing cycles is greater than a pre-set time period.
The dispenser of the present invention may also have a suck back mechanism located between the outlet of the pump and the dispensing tube. The suck back mechanism serves to prevent fluid remaining in the dispensing tube from dripping from the nozzle between uses.
In one embodiment of the present invention, the pump may be a foaming pump which draws a foam precursor from the reservoir through the inlet. The foaming pump combines a gas with the foam precursor to form a foam.
In another embodiment, provided is a method of dispensing a fluid to a user from a fluid dispenser. This method includes providing a fluid dispensing system having sensor, a motor and a pump. The method detects the presence of a current user requesting a fluid from the dispensing system and determines a time lapse period between a previous request for fluid and the current requests for fluid. This time lapse period is compared to a pre-set time period. Next a motor is activated for a single cycle if the time lapse period is less than the pre-set period of time or for multiple cycles if the time lapse is greater that the set period of time.
The fluid which may be dispensed in the process and dispenser of the present invention may be a liquid soap, a liquid sanitizer, a gel soap, a foam soap precursor or a foaming sanitizer precursor.
In a further embodiment of the present invention, the pre-set time period is between about 10 minutes and about 6 hours. When the fluid is a foam soap or sanitizer, the pre-set time period is correlated to a liquefaction time of the foam. Generally, the pre-set time between about 10 minutes and about 1 hour, when the fluid being dispensed is foam from a foam precursor.
In yet further embodiments of the present invention, additional features which may be present in the dispenser include the nozzle is mounted above the counter via a mounting means which extends through the counter. The present invention may also have a power supply connected to the processor, sensor and motor.
In a particular embodiment of the present invention, the multiple cycles is two or three cycles.
In one particular embodiment, the dispenser and method of the present in invention the dispenser dispenses a volume of fluid between between about 0.45 ml and about 2.0 ml. In a more particular embodiment, the dispenser dispenses a volume of fluid between about 0.55 ml and about 0.65 ml.
The present invention provides an easy to maintain fluid dispenser which will dispense an appropriate amount of fluid to effectively clean a user's hand, even if the dispenser has been idle for an extended period of time.
It should be noted that, when employed in the present disclosure, the terms “comprises”, “comprising” and other derivatives from the root term “comprise” are intended to be open-ended terms that specify the presence of any stated features, elements, integers, steps, or components, and are not intended to preclude the presence or addition of one or more other features, elements, integers, steps, components, or groups thereof.
In the following detailed description of the present invention, reference is made to the accompanying drawings which form a part hereof, and which show by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that mechanical, procedural, and other changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
The dispenser of the present invention may be an in-counter dispenser or a above-counter dispenser. The above-counter dispenser may be a wall mounted dispenser such that the fluid is conveyed to the delivery spout via a delivery tube between the pump and the nozzle. Generally, however, the present invention will be more useful in in-counter dispensers. Therefore, the present invention will described in terms of the in-counter dispenser which is mounted through the counter in a restroom or other facility where hand cleaning or sanitizing may be needed.
To gain a better understanding of the present invention, attention is directed to the Figures of the present specification.
The dispenser fixture 12 includes an under-counter portion 24 having a mounting system 25 securing the dispenser fixture 12 to the counter. The mounting system 25 has an elongated tube 26, which is a generally elongated hollow tube, extending through a hole defined in counter 11. By “hollow”, it is intended that a tube has a passage or channel (not shown in
The under-counter portion 24 also has a connecting member 30, located at the distal end 26D of the elongated tube 26. The connecting member 30 is removably connected to the distal end 26D of the elongated tube 26 at a top end of the connecting member 30. The connecting member 30 supports a reservoir assembly 32 which contains the fluid which is to be dispensed from the dispenser apparatus 10. The reservoir assembly 32 is removably connected to the connecting member 30 to the lower end 31 of the connecting member, also referred to as the reservoir assembly connecting surface, such that the reservoir assembly 32 can be removed and replaced when the fluid has been expended from the reservoir assembly 32.
The dispensing apparatus 10 further has a motor housing 202 which is positioned between the distal end 26D of the elongated tube 26 and the connecting member. The motor housing 202 may also contain the control electronics which controls the automatic nature of the dispensing apparatus 10. Attached to the motor housing is a power supply housing 204, which holds the power supply or transformer used to power the automatic dispensing apparatus 10 of with the scope of the present invention.
Referring to
The reservoir assembly 32 has a dispensing tube 119 which extend out of the dispenser assembly. The dispensing tube 119 is generally an elongated tube which carries the fluid to be dispensed from the pump 114 (shown in
Located within the main container 121 is a pump 114, shown in
As shown in
As is shown in
To gain a better understanding of an exemplary pump that may be used in the present invention, attention is again directed to
An engaging element or attenuator 126 is in communication to the pump's piston assembly 61. Typically, the attenuator 126 will be physically connected to the piston assembly 61. In the illustrated embodiment, attenuator 126 is configured has a cylindrical portion 79, and a disc-shaped flange 80. It is generally the cylindrical portion 79 which is connected to the piston 61 of the pump 114. Typically, the attenuator 126 is generally located near the central axis of the reservoir assembly 32, which provides advantages discussed below. Other features of the attenuator 126 are an upper structure 127 and a lower structure 128 which are connected by a connecting structure 129. The upper structure has a top surface 132. Reciprocative movement of attenuator 126 will cause piston assembly 61 to move within the pump cylinder 66. Piston assembly 61 is normally urged into an upward position (rest position), shown in
As is stated above, the pump assembly 114 shown in
Pump device 114 is further provided with additional check valves 84, 85 and 86 to ensure proper flow of the liquid through the pump. Check valve 86, located at the base of pump cylinder 66, allows the liquid 22 to be drawn into a lower liquid chamber 69, through the inlet 141 of the pump when the inner piston 64 moves in an upward direction (charging stage). When inner piston 64 moves in a downward direction (discharging stage), check valve 85 allows the liquid 22 to be passed into an upper liquid chamber 90 from the lower liquid chamber 69. In addition, check valve 84 allows fluid to exit the upper pump chamber 90 into the mixing chamber 92. Both check valves 84 and 85 are opened at the same time and close at the same time. In the mixing chamber 92, air from the air chamber 68 is mixed with the liquid 22 from the upper liquid chamber 90. The mixing of the air and liquid creates a foam fluid which is forced through a porous member 93. The porous member 93 is in the form of a porous net or screen-like structure to create uniformity in the foam bubbles of the fluid. The fluid is then force through the outlet 142 of the pump 114. While a variety of different check valve configurations are contemplated, the illustrated embodiment utilizes common ball and seat valves. Other configuration of these elements may be used without departing from the scope of the present invention. Other structures and functional elements, such as seals and gaskets may be used in the pump device to the pump form leaking or improve the function of the pump. As is stated above, the pump 114 is described as a foaming pump; however, a foaming pump is one specific embodiment of the present invention. Non-foaming pumps may also be used in the dispenser of the present invention as a second embodiment.
The fluid leaving the outlet 142 of the pump 114 is transported to the elongated tube 119 via a flexible tube 96. Generally, the outlet 142 of the pump 114 typically moves with the piston assembly 61. To counter act this movement, the outlet 142 of the pump 114 a flexible tube 96 has a first end 97 attached to the pump outlet 142. The second end 98 of the flexible tube 96 is attached to an inlet 162 of a stationary member 174, is shown in
A suck back mechanism 116 may be optionally included within the dispenser. Suck back mechanisms are described in U.S. patent application Ser. No. 12/329,904, filed on Dec. 8, 2008, which is incorporated by reference, and provides a means to prevent the dispenser from dripping into the sink between uses. Generally, the suck back mechanism 116 is separate and distinct element from the pump 114. Also the suck back mechanism 116 has at least one resilient member 161 capable of storing fluid which may be connected to the stationary member 174. The resilient member 161 is generally hollow structures having an opening 172 located near the portion of resilient member 161 which is to be positioned at or near the stationary member 174. The hollow portion 173 of the hollow structure allows the resilient member 161 to store the fluid. Generally, the suck back mechanism 116 operates by forcing the hollow structure of the resilient member 161 is to collapse, thereby forcing the fluid within the hollow portion 173 out of the hollow portion. Then the resilient member 161 is allowed to its original shape and size, which creates a vacuum, which causes the fluid to be refilled in the resilient member. Generally, at the end of the discharging stage of the pump 114, undispensed fluid remains between the dispensing end 118 and the second opening 163 of the stationary member 174. A portion of the undispensed fluid is drawn into resilient member 161, which prevents the undispensed portion from dripping out of the dispensing end 118 of the dispensing tube 119 and helps prevent stringing of the fluid dispensed to the user with the undispensed fluid. The suck back mechanism 116 may operate independently from the pump 114 or may operate in conjunction with the pump 114. When operated separately from the pump, the suck back mechanism does not rely upon the recovery means 143 of the pump. When operated in conjunction with the pump, the pump's recovery means 143 assists recovery of the resilient members during the charging stage of the pump. The first opening 162 of the stationary member 174 is connected to the outlet 142 of the pump 114.
Optionally, one further element that may be present is a filling port 23, as is shown in
To activate the actuator 126 to dispense the fluid from the dispenser apparatus 10, an actuator rod 130 contacts the top surface 132 of the actuator 126, as is shown in
As the actuator rod 130 depresses the actuator 126, the actuator 126 depresses the piston assembly 61, including both the outer tubular piston 62 and the inner tubular piston 64 of the pump, transitioning the pump 114 from the rest stage to the discharging stage. Depressing the resilient members 161, when present, also causes any fluid within the hollow portion 173 to be expelled from the resilient members 161 into the passage 175 and towards the dispensing end 118 of the dispenser. In addition, fluid is expelled from the pump 114 through the outlet 142 of the pump 114 into the flexible tube 96, which carries the passage 175. The fluid enters the passage 175 and joins the fluid expelled from the resilient member 161, when present. The fluid is also expelled from the delivery spout 20 of the dispenser 10. At the end of the actuator's 26 depressing the resilient member 161, when present, and the piston assembly 61 of the pump 114, the pump recovery means 143 causes the pump to transition from the discharging stage to the charging stage. During the charging stage of the pump 114, the actuator 126 is returned to its rest position, shown in
In the present invention, the dispenser assembly 10 is a hands-free dispenser. As such, dispenser assembly 10 is electronically actuated by an electronic means such as a motor. In one embodiment, the sensor 21 is selected such that the sensor 21 is able to detect a user's hands under the spout 20. The sensor 21 may be an IR sensor or other similar type of sensors could sense a user's hands under the spout 20. When the sensor 21 detects a user's hands under the spout 20, the sensor 21 sends a signal to the control circuitry that a user has requested a dose of the fluid by placing their hands under the spout. The control circuitry in turn sends a signal to a motor 210, shown in
In a particular embodiment, the sensor 21 is electrically connected to a control panel (not shown) having control circuitry 500, shown in
Typically, the power supply housing 204 may be separated from the motor housing so that the power supply may be replaced when needed. That is, the power supply is disconnectable and reconnectable to the motor housing 202. To ensure that power is transferable from the power supply 205 in the power supply housing 204 to the motor housing 202, electrical contact points may be used on both the motor housing 202 and power supply housing 204. These electrical contact points are in complementary positions, meaning that when the power supply 205 in the power supply housing 204 is attached to the motor housing 202, an electrical connection is made. The power supply 205 powers the entire unit, including the sensor 21, control circuitry 500, including the processor and the motor 210.
The power supply 205 for the fluid dispensing system of the present invention may include disposable DC batteries (not shown). Alternatively, the power supply 205 may be a closed system which requires that the entire power supply be replaced as a single unit. Although not shown in the figures, an AC to DC adapter/transformer may be utilized to provide an alternate source of power to the fluid dispenser. This embodiment may be particularly useful wherein the fluid dispenser is mounted in close proximity to an AC outlet or when it is desirable to power multiple dispensers from a centrally located transformer of suitable configuration and power. The number of batteries used to power the motor will depend on the motor selected for the dispenser. Disposable batteries useable in the present invention include 9 volt batteries, 1.5 volt batteries, such as D-cell or C-cell batteries, or other similar batteries. The exact type of battery selected for use is not critical to the present invention so long as the power supplied to the motor is compatible for the motor. For applications where the fluid dispenser will be used under low usage situations, rechargeable batteries could be used. If the dispenser is to be used in a bright light situation, the batteries could be solar rechargeable batteries.
Once the processor receives the input from the sensor, the processor sends power to the motor 210, which in turn actuates the pump. To gain a better understanding of a possible configuration of the motor housing 202, attention is now directed to
Numerous ways may be used to transfer power from an activated motor 210 to the motor driven actuator rod 130. For example, the motor 210 may drive a series of wheels, gears or other energy transmission means to the actuator rod 130 which extends and contacts the actuator 126. In one embodiment of the present invention, which is intended to be an exemplary means that may be used to drive the actuator rod 130, the drive wheel 213 has a post or shaft 214 extending from one area of the gear body near the periphery 215, as is shown if
As is shown in
As is mentioned above, the shaft 214 also has a horizontal movement 326 in the horizontal axis 2. This horizontal movement is essentially unwanted. To account for the horizontal movement, the shaft is allowed to move horizontally in the horizontal axis 2 along the channel 322 in the actuator guide member. Therefore, the channel 322 controls the essentially unwanted horizontal movement 326 of the shaft 214.
The hands-free fluid dispensing systems may also have additional features. For example, dispensing head 18 may have indicator lights to signal various events, such as, recognition of a user, low battery, empty soap reservoir, or other conditions such as a motor failure. Examples of such lights include low power consumption lights, such as LED (light emitting diodes).
In the present invention, the control circuitry 500 contains a processor 510 which has an on-board clock. The processor 510 is in communication with both the sensor 21 and the motor 210. A general diagram of a control circuit 500 which may be used in the present invention is shown in
The processor 510 is configured to determine a time interval between dispensing cycles. The processor 510 has an on-board clock function which determines the time between requests for the fluid. The processor 510 determines the lapsed time between the current request for soap from the user and the previous request for soap. If the time difference is greater than a preset time, the processor 510 will send a signal to the motor drive circuit indicating that a larger amount of soap needs to be dispensed. In the present invention, the processor 510 and motor drive circuit 514 can activate the motor for a single cycle or for multiple cycles. As used herein, a cycle is one attenuation of the pump to dispense a single shot of the fluid.
The processor 510 has a clock function which is able to keep time between a current request for the fluid and a previous request for the fluid. When the time period is greater than a preset time period, the processor 510 will instruct the motor 210 to activate for two or more cycles. This instruction will run through the motor drive circuit 514 as shown in
In the present invention, the fluid dispensed from the dispenser may be a variety of fluids. Generally, the fluid dispensed will be a hand cleaning fluid, such as liquid soap, a liquid sanitizer, a gel soap, a foam soap precursor, a foaming sanitizer precursor or other similar hand cleaning or sanitizing liquid formulations. It is noted in the case of foaming soap precursor, or a foaming sanitizer precursor, these formulations are liquids before a foaming pump will convert these fluid to a foam.
Selection of the fluid that will be dispensed from the dispenser will affect conditions which will be used to dispense the fluid, including the pump and the pre-set time period. If the fluid to be dispensed is a foam precursor, the pre-set time period will be based on factors, such as the time period in which liquefaction of the foam soap occurs, temperature, pressure and other similar factors. Generally, preset time period will be set to a period of time which is liquefaction of the particular foam soap occurs being dispensed from the dispenser, or a period shorter than the liquefaction of the foam soap occurs. Generally, liquefaction of foam soaps occurs within about 1 hour. Therefore, the preset time period should be a time period of about 1 hour or less. In one embodiment of the present invention, the preset time is set for a period of time which is approximately one-half of the time in which liquefaction of the foam will occur. For example, if liquefaction occurs in 1 hour, the preset time would be set for 30 minutes. For most foam soaps and sanitizers, liquefaction occurs generally within 1 hour. Therefore, the preset time for most foam soaps will be set at 1 hour or less, for example, 50 minutes, 45 minutes, 40 minutes, 30 minutes, 20 minutes, 15 minutes, 10 minutes and the like. Generally, the pre-set time period will be between about 10 minutes and about 1 hour.
In the case of liquids (which are not foaming) being dispensed from the fluid dispenser, the pre-set period of period will generally be longer and will depend on conditions such as evaporation rate of the fluid, temperature, pressure and the components of the liquid. For liquids, the pre-set time period could be in the range of about 10 minutes and about 6 hours, or even longer.
Other features can include product recognition, where the reservoir assembly 32 has a product identification feature which can communicate with the control circuitry to identify the product being dispensed, or other features such as the size of the fluid pump in the reservoir assembly, the type of pump (fluid or liquid). The control circuitry would have a means to receive the product identification information. Exemplary product identification means includes RFID, optical sensor such as a bar code reader and other similar means. The processor could then adjust the preset time according to the product being dispense to account for the specific liquefaction time for the product being dispensed. In addition, other conditions, such as temperature and pressure could also be communicated to the processor, so that the preset time could be adjusted according to the environmental conditions.
In the present invention, if the lapsed time between dispensing events is larger than the pre-set time period, the motor 210 is operated such that multiple doses of the soap is dispensed. By multiple doses, it is intended to mean 2 or more doses in succession. Generally, only 1 or 2 additional attenuations of the pump are necessary in the present invention, but there could be more in the event of liquefaction. When multiple doses of the fluid are to be dispensed, the dispensing time between doses should be as short as possible. If the period is too long, the user will withdraw their hand or hands before the second or subsequent dose is dispensed. Typically, the multiple doses should occur in under 5 seconds, more desirably, under 2 seconds. Generally, the shorter the time period between doses, the better. In one embodiment of the present invention, the multiple doses are dispensed within about 0.5 seconds, typically between about 0.1 and 0.5 seconds.
Also, the control circuitry may include mode for start-up or replacement of the reservoir assembly. In such a mode, the processor would instruct the motor control circuit 514 to attenuate the pump through several cycles. Further, the control circuitry may have a delay circuit built in such that in a situation where the time between dispensing intervals is less than the pre-set time period, the motor will only attenuate the pump once for a set short period of time, such as 0.5 to about 2 seconds. This will prevent users from using too much fluid during a hand washing event.
Another feature which may be present in the fluid dispenser of the present invention is additional switches which may set the fluid dispenser to only dispense a single shot, or always dispense a double shot. A third setting on this switch would be for the dispenser to operate as described herein, dispensing a double shot of foam, if the time between dispensing is longer than a pre-set time period. Other switches or adjustments that could be used in a variable resistance switch which could be used to adjust and change the pre-set time period. Yet another switch could be used to set the type of fluid to be dispensed from the fluid dispenser.
The fluid dispenser of the present invention will generally delivery as much fluid soap necessary for a hand cleaning event. Generally, the amount of fluid will be up to about 3 ml or more of the fluid, depending on the nature of the hand cleaning or sanitizing fluid. For industrial applications, the upper limit for the amount of fluid being dispensed could be higher than 3 ml. For most hand washing events, the amount of the fluid will be less than 2 ml, and generally less than 1 ml. In a particular embodiment, the amount of the precursor delivered by the fluid dispenser is between about 0.45 ml and about 0.8 ml and more particularly, between 0.45 ml and 0.55 ml.
The present invention is also directed to a method of dispensing a fluid to a user from a fluid dispenser. This method has the steps of
The method of the present invention is shown graphically in
As an alternative embodiment, rather than calculating the lapse time, the processor could be set up with a timer. In such a configuration, the lapsed time is determined from the timer. At box 505, the timer is rest to zero and the time on the timer at box 505 is the lapsed time, which is compared to the set time Ts.
Obtaining multiple cycle operation of the motor, can be accomplished in different methods. One method, the processor will provide a higher voltage to the motor, which will make the motor run faster to dispense the fluid. Another method is to have a motor which runs as quick as necessary to achieve the desired dispensing time.
Although the present invention has been described with reference to various embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. As such, it is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is the appended claims, including all equivalents thereof, which are intended to define the scope of the invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4722372 | Hoffman et al. | Feb 1988 | A |
| 4938384 | Pilolla et al. | Jul 1990 | A |
| 4967935 | Celest | Nov 1990 | A |
| 5305916 | Suzuki et al. | Apr 1994 | A |
| 5449117 | Muderlak et al. | Sep 1995 | A |
| 5507413 | Chen | Apr 1996 | A |
| 6065639 | Maddox et al. | May 2000 | A |
| 6267297 | Contadini et al. | Jul 2001 | B1 |
| 6276274 | Hoffman et al. | Aug 2001 | B1 |
| 6375038 | Daansen et al. | Apr 2002 | B1 |
| 6629150 | Huded | Sep 2003 | B1 |
| 6644507 | Borut et al. | Nov 2003 | B2 |
| 7069941 | Parsons et al. | Jul 2006 | B2 |
| 7458523 | Hyslop | Dec 2008 | B2 |
| 7540397 | Muderlak et al. | Jun 2009 | B2 |
| 7594622 | Witt et al. | Sep 2009 | B2 |
| 20040050876 | Muderlak et al. | Mar 2004 | A1 |
| 20040074935 | Chon | Apr 2004 | A1 |
| 20050247735 | Muderlak et al. | Nov 2005 | A1 |
| 20060076366 | Furner et al. | Apr 2006 | A1 |
| 20070199952 | Carpenter et al. | Aug 2007 | A1 |
| 20080186396 | Nakajima et al. | Aug 2008 | A1 |
| 20090166381 | Phelps et al. | Jul 2009 | A1 |
| 20100140300 | Lewis et al. | Jun 2010 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20110127291 A1 | Jun 2011 | US |
