Patent ID: 12226788

DETAILED DESCRIPTION

While the devices disclosed herein may be embodied in many different forms, several specific embodiments are discussed herein with the understanding that the embodiments described in the present disclosure are to be considered only exemplifications of the principles described herein, and the disclosure is not intended to be limited to the embodiments illustrated. Throughout the disclosure, the terms “about” and “approximately” mean plus or minus 5% of the number that each term precedes.

The present disclosure relates in general to continuous spray dispensers, and more particularly to continuous spray dispensers that implement a pulsation dampener for dispensing a fluid at a constant flow rate. It should be noted that while the fluids highlighted herein are described in connection with a fluid comprising a chemical composition and diluent mixture, the fluid dispensing devices disclosed herein may be used or otherwise adapted for use with any fluid, composition, or mixture.

The dispensing devices disclosed herein have enhanced performance when compared with existing dispensing systems. For example, existing dispensers commonly use single or dual reciprocating piston-type pumps or gear pumps, which are generally known in the art. Single reciprocating piston pumps generally include a piston disposed within a pump chamber, the piston being driven by a motor to intake fluid and subsequently discharge the fluid through a conduit or a nozzle. During the intake step, the piston may linearly translate away from the nozzle, thereby drawing fluid into the pump chamber. During the subsequent discharge step, the piston may be driven toward the nozzle to discharge the fluid out of the pump chamber and through the nozzle. Consequently, pressure within the pump chamber and against the nozzle varies significantly between the intake step and the discharge step. The nozzle generally experiences greater pressure during the discharge step than during the intake step, and, accordingly, the flow rate of fluid through the nozzle is not consistent.

Dual reciprocating piston pumps are designed to provide simultaneous intake and discharge steps so that when the piston draws fluid into the pump chamber, the piston concurrently discharges fluid from the pump chamber. This type of pump generally provides less fluctuation in pressure and, correspondingly, fluid flow rate. However, this type of pump still provides unsteady sprayer patterns, such as a spray pattern50shown applied to a spraying surface52, as illustrated inFIG.1A. The fluid flow out of the nozzle of the dispenser may substantially cease or diminish during the intake step, which results in a series of regions of reduce flow or drop-off regions54. Gear pumps are known to provide a steadier fluid flow than piston pumps, but are less reliable. Therefore, while being capable and adequate for use, gear pumps are not a preferred pump type for such dispensing systems.

The dispensing devices disclosed herein may alleviate this issue and others. Generally, the dispensing devices according to embodiments of the present disclosure utilize a pump assembly that incorporates a pulsation dampener configured to provide a substantially constant fluid flow. For example, dispensing devices according to the present disclosure may provide spray patterns such as a spray pattern58on the spraying surface52shown inFIG.1B. The pulsation dampener used in the dispensing system is configured to reduce fluid pressure fluctuations within the pump chamber and against the nozzle to create a substantially continuous stream of fluid through the nozzle. Therefore, the dispensing devices disclosed herein exhibit enhanced dispensing control and precision when compared to other prior art dispensing devices.

As used herein, a fluid flow may be referred to as being “substantially continuous” or “substantially constant” if a flow rate of the stream of fluid remains substantially within a range that is greater than 0. For example, a substantially constant stream of fluid may have a flow rate that remains between about 1.5 milliliters per second (“ml/s”) and about 4.5 ml/s. In some embodiments, a substantially constant stream of fluid may have a flow rate that remains between about 0.5 ml/s and about 5.0 ml/s, between about 1.8 ml/s and about 3.3 ml/s, or between about 2.0 ml/s and about 3.0 ml/s. A substantially continuous flow rate may remain within a particular range for a duration of time. For example, a substantially continuous stream of fluid may remain between about 1.5 ml/s and about 4.5 ml/s for at least one, three, five, eight, or ten seconds. Further, a substantially continuous stream of fluid may remain between any of the aforementioned exemplary ranges for at least one, four, six, nine, or twelve seconds.

Moreover, a stream of fluid having a substantially constant flow rate may have an amplitude that remains within a particular range, such as, e.g., 15 centimeters (“cm”) or less. More specifically, embodiments of the present disclosure may provide a dispenser that is capable of emitting fluid in a direction along a longitudinal axis that is substantially collinear with a center of the nozzle onto a spraying surface. In some embodiments, if a substantially continuous stream of fluid is emitted onto a spraying surface from about one meter away for a duration of about five seconds, at least 95% of a resulting spray pattern may have an amplitude of 15 cm or less. Similarly, in some instances, if a substantially continuous stream of fluid is dispensed onto a spraying surface from about four meters away for a duration of about ten seconds or less, at least 95% of a resulting spray pattern has an amplitude of 15 cm or less. In some embodiments, at least 90% of the spray pattern has an amplitude of 12 cm or less. In some embodiments, at least 80% of the spray pattern has an amplitude 10 cm or less. Furthermore, in some embodiments, a continuous spray pattern may have a minimum amplitude that is at least 50% of a maximum amplitude of the spray pattern.

A stream of fluid may be emitted for a distance of about one meter, about two meters, about three meters, or about four meters before impacting a spraying surface, and a resulting pattern formed on the spraying surface may be measured to determine continuity. Additionally, a stream of fluid may be emitted onto a spraying surface from a first point to a second point on the surface for a duration of time before being evaluated for continuity. In some embodiments, the first point and the second point on the spraying surface may be at least one meter, at least two meters, at least three meters, or at least four meters away from each other. Generally, a resulting spray pattern is the pattern formed on a spraying surface by a stream of fluid, such as, e.g., the patterns50,58shown inFIGS.1A and1B, respectively.

FIGS.2-15illustrate a dispensing device82and various components of the dispensing device82, according to an embodiment of the present disclosure. Referring particularly toFIG.2, the dispensing device82generally includes a sprayer housing86including a first shell94and a second shell98that can be fastened together with screws or another suitable fastening device. As used herein, the dispensing device82may also be referred to as a dispenser, dispensing system, fluid application system, dispensing mechanism, sprayer device, for example. As shown inFIG.3, the sprayer housing86surrounds a sprayer assembly102that is configured to provide continuous fluid flow and will be described in detail below.

Referring toFIG.2, the dispensing device82may be configured for use with a diluent reservoir106that may be configured to hold a diluent, such as, e.g., water. In some embodiments, a diluent may be a fluid having a viscosity less than about 1.7 millipascal-second (“mPa-s”), less than about 1.5 mPa-s, less than about 1.2 mPa-s, less than about 1.1 mPa-s, or less than about 1.0 mPa-s, the viscosity being taken at temperature of about 20° C. Further, the dispensing device82may be configured to mix a chemical concentrate with a diluent, the chemical concentrate being held within a chemical concentrate container108. The diluent reservoir106and the chemical concentrate container108may be substantially similar to the diluent reservoir and the chemical concentrate container disclosed in U.S. Pat. No. 9,192,949 to Lang et al., the entirety of which is incorporated by reference herein. Any fluid suitable for diluting a concentrated liquid chemical can be used as the diluent. The diluent reservoir106can be formed from a suitable material such as a polymeric material, e.g., polyethylene or polypropylene. The concentrate can be selected such that when the concentrate is diluted with the diluent, any number of different fluid products is formed. Non-limiting example products include general purpose cleaners, kitchen cleaners, bathroom cleaners, dust inhibitors, dust removal aids, floor and furniture cleaners and polishes, glass cleaners, anti-bacterial cleaners, fragrances, deodorizers, soft surface treatments, fabric protectors, laundry products, fabric cleaners, fabric stain removers, tire cleaners, dashboard cleaners, automotive interior cleaners, and/or other automotive industry cleaners or polishes, or even insecticides.

Still referring toFIG.2, the chemical concentrate container108can be formed from a suitable material such as a polymeric material, e.g., polyethylene or polypropylene, and in some embodiments, the chemical concentrate container108comprises a transparent material that allows the user to check the level of chemical concentrate in the chemical concentrate container108. It should be appreciated that the term “chemical” when used to describe the concentrate in the chemical concentrate container108can refer to one compound or a mixture of two or more compounds. Alternatively, the sprayer assembly102disclosed herein may be coupled to any fluid-containing reservoir and configured to dispense the fluid. To that end, the present disclosure is not limited to the diluent reservoir incorporated above; rather, the dispensing device82may be adapted to be coupled to any fluid-containing reservoir for dispensing the fluid contained in the reservoir. In some embodiments, the fluid has a viscosity of about 1.7 mPa-s, about 1.5 mPa-s, about 1.3 mPa-s, about 1.2 mPa-s, about 1.1 mPa-s, or about 1.0 mPa-s. Further, in some embodiments, the fluid has a viscosity less than about 1.7 mPa-s, less than about 1.5 mPa-s, less than about 1.3 mPa-s, less than about 1.2 mPa-s, less than about 1.1 mPa-s, or less than about 1.0 mPa-s. In some embodiments, the fluid may have a viscosity between about 0.5 mPa-s and about 1.1 mPa-s, between about 0.9 mPa-s and about 1.7 mPa-s, or between about 0.8 mPa-s and about 1.1 mPa-s.

Referring again toFIG.3, the sprayer housing86includes the first shell94and the opposing second shell98. The first shell94and the second shell98may be mirror images of one another such that the sprayer housing86is substantially symmetrical. In some embodiments, the first and second shells94,98may have complementary or similar shapes, but may have different design features. Further, the first and second shells94,98are configured to attach to one another to define an internal cavity118that may contain the sprayer assembly102therein. The first and second shells94,98may be connected via press-fit, fasteners, adhesives, integrally formed latches, snaps, or the like. The sprayer housing86may additionally include a rear shell cap122that may be attached to the first and second shells94,98to assist in defining the internal cavity118. Referring toFIG.4A, removal of the rear shell cap122may permit access to the internal cavity118at a rear end126of the sprayer housing86while the first shell94is still connected to the second shell98. At a front end128of the sprayer housing86opposite the rear end126, the first and second shells94,98may define a nozzle opening130that is configured to receive and/or retain a nozzle134.

Referring now toFIG.5, the sprayer assembly102that is disposed within the sprayer housing86includes a pump assembly142and a gearbox assembly146. The gearbox assembly146comprises an electric motor150and a transmission154, whereas the pump assembly142includes a pump162, the nozzle134, and a pulsation dampener166. The motor150includes a drive gear, and the transmission154includes a series of gears (not shown). A cam follower174and a cam follower shaft178(seeFIG.6) are also provided with the gearbox assembly146for driving the pump assembly142. A battery box182that is configured to hold one or more batteries186(seeFIG.3), such as, e.g., AA or AAA-type batteries, is additionally provided to power the motor150. Each of these components may be arranged within the sprayer housing86in a variety of configurations. However,FIG.5illustrates a preferred arrangement according to the present embodiment. As shown, the battery box182is provided adjacent the motor150, and the pump162is disposed between the nozzle134and the motor150. A trigger190is arranged proximate the nozzle134and is configured to contact a microswitch194when depressed. In some embodiments, the battery box182may be arranged between the pump assembly142and the motor150. In some embodiments, the motor150may be arranged adjacent the pump assembly142and proximate the front end128of the housing86. Furthermore, in some embodiments, the pump assembly142may be disposed between the battery box182and the motor150.

Still referring toFIG.5, when assembled in the sprayer housing86, the pump assembly142, which includes the nozzle134and a nozzle cover198, is arranged proximate the front end128of the sprayer housing86such that the nozzle cover198protrudes into or through the nozzle opening130defined by the sprayer housing86. Turning now toFIG.6, in the assembled configuration, a center of the nozzle134defines a longitudinal axis206, the longitudinal axis206being collinear with the center of the nozzle134, and the pump assembly142is arranged along the longitudinal axis206, extending from the nozzle opening130toward the rear end126of the sprayer housing86. Generally, the dispensing device82may be configured to dispense the fluid in a direction along the longitudinal axis206. The motor150, which is provided with the gearbox assembly146, is arranged adjacent the pump assembly142, between the pump assembly142and the rear shell cap122of the sprayer housing86, and similarly disposed along the longitudinal axis206. Referring toFIG.6, a push rod210of the gearbox assembly146is coupled to the cam follower174of the pump assembly142so that, when the gearbox assembly146is driven by the motor150, the push rod210drives the cam follower174to operate the pump162, i.e., drive a piston.

Referring toFIG.7, the battery box182is arranged adjacent the motor150and gearbox assembly146so that it extends from proximate the pump assembly142toward the rear side of the sprayer housing86. In the illustrated embodiment, the battery box182is an elongate body that is arranged substantially along axis218that is disposed at an angle α relative to the longitudinal axis206. In some embodiments, the angle α may be between about 5 degrees and about 50 degrees. In some embodiments, the angle α may be between about 10 degrees and about 25 degrees. In some embodiments the angle α may be about 8 degrees, about 12 degrees, about 15 degrees, about 18 degrees, or about 20 degrees. Alternatively, in some embodiments, the battery box182may be arranged substantially parallel to the longitudinal axis206, i.e., the angle α is about zero degrees.

Referring toFIG.8, the battery box182is a generally hollow body having an insertion opening222that faces the rear end126of the sprayer housing86configured for receiving the batteries186. Generally, the battery box182is disposed proximate the rear end126of the sprayer housing86such that when the rear shell cap122of the sprayer housing86is removed, batteries186can be inserted into and/or removed from the battery box182. A length of the battery box182measured along the axis218may be no more that 50% of a length of the sprayer housing86measured along the longitudinal axis206. In some embodiments, the length of the battery box182may be no more than 30%, 40%, 60%, or 70% of the length of the sprayer housing86.

Still referring toFIG.8, the trigger190is hingedly attached to the sprayer housing86proximate the pump assembly142. More specifically, the trigger190is hingedly attached at a first end226thereof such that it is disposed within a trigger opening230defined by the sprayer housing86, i.e., defined between the first shell94(not shown inFIG.8) and the opposing second shell98. Therefore, the trigger190may be depressed into the sprayer housing86to contact the microswitch194. When contacted by the trigger190, the microswitch194may permit the flow of electricity from the batteries186to the motor150to operate the pump162, which will be described in greater detail below. More specifically, the motor150, by way of the transmission154and the push rod210, drives the cam follower174, which, in turn, reciprocates a piston242(seeFIG.11) within a pump chamber246of the pump162to draw fluid into the pump chamber246and then expel the fluid from the nozzle134.

Sprayer assemblies according to embodiments of the present disclosure are generally configured for use in handheld dispensing systems. Therefore, sprayer assemblies according to embodiments of the present disclosure, such as the sprayer assembly102shown inFIG.5, may have size limitations. For example, and referring again toFIG.5, the components of the sprayer assembly102must be arranged and sized so that they may fit within the sprayer housing86. In the illustrated embodiment, the sprayer housing86defines the internal cavity118having a volume of about 150 cubic centimeters (“cm3”). In some embodiments, the internal cavity118may have a volume of about 125 cm3, about 170 cm3, about 190 cm3, or about 200 cm3. Further, in some embodiments, the internal cavity118may be no greater than about 225 cm3, about 250 cm3, or about 300 cm3.

Correspondingly, the components of the sprayer assembly102must fit within the internal cavity118and, thus, must occupy a volume less than the volume of the internal cavity118. The sprayer assembly102thus may have a volume of about 90 cm3. Alternatively, the sprayer assembly102may occupy a volume of about 65 cm3, about 78 cm3, about 85 cm3, about 96 cm3, about 125 cm3, about 142 cm3, or about 164 cm3in some embodiments. Further, in some embodiments, the sprayer assembly102may occupy a volume no greater than about 88 cm3, about 100 cm3, about 112 cm3, or about 200 cm3. The volume of the sprayer assembly may be between about 65 cm3and about 105 cm3, between about 70 cm3and about 88 cm3, between about 80 cm3and about 92 cm3, or between about 100 cm3and about 150 cm3.

Each of the components of the sprayer assembly102may accordingly have volume limits. For example, in some embodiments, the pump assembly142, which includes the pump162and the pulsation dampener166, may have a volume of about 35 cm3, about 48 cm3, or about 58 cm3. In some embodiments, the pump assembly142may have a volume of between about 25 cm3and about 50 cm3, between about 28 cm3and about 46 cm3, or between about 32 cm3and about 45 cm3. In some embodiments, the pump assembly142may occupy no more than 25% of the volume of the internal cavity118. Furthermore, in some embodiments, the pump assembly142may occupy no more than about 15%, about 30%, about 35%, about 45%, about 48%, about 50%, or about 60% of the volume of the internal cavity118. The pump assembly142and the gearbox assembly146, which includes the motor150and the transmission154, combined may occupy a volume of about 60 cm3, about 74 cm3, or about 80 cm3.

In some embodiments, the pump assembly142and the gearbox assembly146may collectively occupy no more than 40% of the volume of the internal cavity118. Moreover, in some embodiments, the pump assembly142and the gearbox assembly146together may occupy no more than about 35%, about 47%, about 54%, about 63%, about 75%, or about 80% of the volume of the internal cavity118. Components of the sprayer assembly102may similarly have a footprint limit. For example, in some embodiments, the pump assembly142including the pump162and the pulsation dampener166, and the gearbox assembly146including the motor150and the transmission154are disposed entirely within a footprint of about 72 cm3. In some embodiments, the footprint may be about 60 cm3, about 75 cm3, about 80 cm3, or about 84 cm3. Moreover, the pump assembly142and the gearbox assembly146may be disposed entirely within a footprint of less than about 70 cm3, about 73 cm3, about 78 cm3, about 82 cm3, about 90 cm3, or about 100 cm3.

Turning again toFIG.7, when assembled, a longitudinal length of the gearbox assembly146taken along the longitudinal axis206must be less than a longitudinal length of the sprayer housing86measured along the longitudinal axis206. In some embodiments, the longitudinal length of the gearbox assembly146may be less than about 30%, about 40%, about 50%, about 60%, or about 70% of the longitudinal length of the sprayer housing86. In some embodiments, the longitudinal length of the gearbox assembly146may be between about 20% and about 45% of the longitudinal length of the sprayer housing86. Likewise, a longitudinal length of the pump assembly142measured along the longitudinal axis206must be less than the longitudinal length of the sprayer housing86along the longitudinal axis206. In some embodiments, the longitudinal length of the pump assembly142is less than about 30%, about 40%, about 50%, about 60%, or about 70% of the length of the sprayer housing86. In some embodiments, the longitudinal length of the pump assembly142may be between about 20% and about 55% of the longitudinal length of the sprayer housing86. In combination, a longitudinal length of the gearbox assembly146and the pump assembly142similarly must be less than the longitudinal length of the sprayer housing86. In some embodiments, the longitudinal length of the gearbox assembly146and the pump assembly142collectively may be between about 50% and about 80%, about 60% and about 90%, or about 70% and 100% of the longitudinal length of the sprayer housing86.

Referring now toFIGS.9-11, the pump assembly142is shown in greater detail. Referring specifically toFIG.11, the pump assembly142includes the pump162having the piston242that is linearly displaceable within the pump chamber246, e.g., a pump cylinder. The pump chamber246defines an inside diameter D1(see alsoFIGS.14and15) and is in fluid communication with a discharge conduit250, which is in fluid communication with the nozzle134. The inside diameter D1of the pump162may also be referenced as the inside diameter D1of the pump piston242. Generally, the discharge conduit250is in fluid communication with an outlet254of the pump chamber246and with an inlet258of the nozzle134through which the fluid can be dispensed when the pump162is activated. Similarly, the pump chamber246is in fluid communication with a pump supply conduit266that is placed in fluid communication with a fluid supply conduit268(seeFIG.12) by way of a sprayer connector, which is further described in U.S. Pat. No. 8,403,183 to Fahy et al., which is incorporated herein by reference in its entirety. Therefore, as will be described in greater detail below, the piston242is configured to linearly move within the pump chamber246to intake and discharge fluid through the pump supply conduit266and the discharge conduit250, respectively. An external O-ring278is provided around the piston to assist in clearing the pump chamber246. The O-ring278enhances the pump suction to draw in and push out the fluid being dispensed. Although one O-ring is depicted, it should be understood that other embodiments can use a different number of O-rings.

Still referring toFIG.11, in addition to the piston242and the O-ring278disposed within the pump chamber246, the pump assembly142further includes a plurality of valves282and the cam follower174. Further, the pump assembly142has a main pump housing286that may receive and house components of the pump162, in addition to a pump cover290that may be attached to the main pump housing286. The pump162may further include a first pump body298and a second pump body302that retain the piston242and its shaft244, the first and second pump bodies298,302being configured for insertion into the main pump housing286. A housing O-ring306may be utilized to provide a seal between the main pump housing286and the pump cover290. Furthermore, the nozzle134, which includes a nozzle orifice314, and the nozzle cover198may be provided for attachment to a nozzle body322that couples to the pump162and the pulsation dampener166. The assembled pump assembly142is shown inFIGS.9and10.

Still referring toFIG.11, the pump162may be a single or dual reciprocating piston-type pump, which are generally known in the art. Thus, the typical operation of this pump type is known; however, for purpose of description, an overview is provided below. Generally, in the instance of a single reciprocating piston pump, the pump162is driven by the motor150via the transmission154and the push rod210. The push rod210is configured to drive the piston242of the pump162between an intake step and a discharge step. During the intake step, the piston242may linearly translate away from the nozzle134, thereby drawing fluid, via the pump supply conduit266, into the pump chamber246. During the subsequent discharge step, the push rod210drives the piston242toward the nozzle134, thereby discharging the fluid, via the discharge conduit250, out of the pump chamber246and through the nozzle134.

Consequently, in instances where the pump162operates without a pulsation dampener, pressure within the pump chamber246and against the nozzle134naturally varies significantly between the intake step and the discharge step. More specifically, in the absence of a pulsation dampener the nozzle134experiences greater fluid pressure during the discharge step than during the intake step. Furthermore, fluid flow through the nozzle134is not continuous. Rather, fluid flow out of the nozzle134ceases or is diminished during the intake step, similar to the spray pattern50previously discussed in connection withFIG.1A. A dual reciprocating piston-type pump operates substantially similarly to the single reciprocating piston-type pump described above.

However, rather than having a single pump chamber with an intake step and a discharge step, the pump162may have concurrent intake and discharge steps. That is, as the piston242draws fluid into the chamber246through a first inlet, it may be discharging fluid through a first outlet. As the fluid is being discharge through a second outlet, fluid may be drawn into the pump chamber246via a second inlet. Thus, the piston242may divide the chamber into two regions that each draw in and discharge fluid in opposing steps. The use of a dual reciprocating piston-type pump diminishes pulsation and create a steadier, more continuous fluid flow than a single reciprocating piston-type pump. However, dual reciprocating piston-type pumps still experience at least some fluid flow cessation, like the regions of reduced flow54shown inFIG.1A. Thus, embodiments of the present disclosure are generally designed to diminish pressure fluctuations within the pump chamber246and mitigate fluid flow irregularities that are typically experienced by existing dispenser systems by incorporating the pulsation dampener166. The pulsation dampener166is designed to decrease or diminish flow stalling or reduction that occurs when the pump162is operating.

Referring particularly toFIG.11, the pulsation dampener166of the pump assembly142includes a dampener piston330that is linearly displaceable within a dampener housing334using a dampener spring338, thereby defining a variable volume headspace342within the dampener housing334. The dampener piston330and the dampener spring338are used to dampen pressure increases during the intake step of the pump162by moving within the dampener housing334to change the volume of the headspace342. In some embodiments, a maximum volume of the headspace342is in a range of about 2.0 milliliters (“ml”) and about 6.0 ml. In some embodiments, the maximum volume of the headspace342may be between about 1.0 ml and 6.5 ml, between about 3.0 ml and 5.0 ml, or between about 3.5 ml and 4.5 ml. Furthermore, the variable volume headspace342may have an average volume of about 2.5 ml, about 2.8 ml, about 3.4 ml, about 3.7, or about 4.2 ml. In some embodiments, the average volume of the headspace342may be between about 0.5 ml and about 3.5 ml, between about 1.2 ml and about 3.2 ml, or between about 1.5 ml and about 3.0 ml. The variable volume headspace342additionally may have a minimum volume of about 0.2 ml, about 0.4 ml, about 0.8 ml, about 1.0 ml, or about 1.4 ml. The minimum volume in some embodiments may be less than about 0.5 ml, about 0.7 ml, about 1.0 ml, or about 1.5 ml. A deflection of the dampener spring is related to the maximum volume of the headspace342. In some embodiments, a maximum deflection of the dampener spring is about 3.5 mm, about 4.0 mm, about 4.5 mm, about 5.0 mm, or about 5.5 mm. In some embodiments, the maximum deflection is between about 3.5 mm and about 4.5 mm, between about 4.0 mm and about 5.0 mm, or between about 4.5 mm and about 5.5. Further, in some embodiments, the maximum deflection is no greater than about 3.8 mm, about 4.3 mm, about 4.8 mm, about 5.2 mm, or about 5.6 mm.

Referring toFIG.13, the headspace342has an inside diameter D2(see alsoFIG.15). The inside diameter D2of the pulsation dampener166may also be referenced as the inside diameter D2of the pulsation dampener piston330. In some embodiments, the inside diameter D2of the pulsation dampener166may be between about 0.5 centimeters (“cm”) and about 2.0 cm, about 1.0 cm and about 1.8 cm, or about 1.2 cm and about 1.5 cm. In some embodiments, the inside diameter D2may be about 1.0 cm, about 1.1 cm, about 1.2 cm, about 1.3 cm, and about 1.4 cm. In some embodiments, the inside diameter D2may be no greater than about 1.4 cm, about 1.6 cm, or about 2.0 cm. Further, referring toFIG.15, a ratio of the inside diameter D1of the pump162to the inside diameter D2of the pulsation dampener166may be in a range of between about 1:0.5 and about 1:2. In some embodiments, the ratio of the inside diameter D1of the pump162to the inside diameter D2of the pulsation dampener166may be in a range of between about 1:1.3 and about 1:3.6. In some embodiments, the ratio of inside diameter D1of the pump162to the inside diameter D2of the pulsation dampener166is about 1:0.6, about 1:0.8, about 1:1, about 1:1.2, about 1:1.4, about 1:1.6, about 1:1.8, about 1:2, about 1:2.2, or about 1:2.4. Further, the inside diameter D1of the pump162may be about 70% of the inside diameter D2of the pulsation dampener166. In some embodiments, the inside diameter D1of the pump162is about 20%, about 25%, about 28%, about 35%, about 38%, about 42%, about 46%, about 50%, about 53%, about 56%, about 60%, about 63%, about 66%, about 68%, about 72%, about 75%, about 77%, about 82%, about 86%, about 90%, or about 100% of the inside diameter D2of the pulsation dampener166. Furthermore, the inside diameter D2of the pulsation dampener166may be about 50%, about 54%, about 60%, about 66%, about 70%, about 75%, about 80%, or about 90% of the inside diameter D1of the pump162. The ratio/relationship of these diameters may play a significant role in the performance of the dispensing device82, which will be described in greater detail below. Additionally, in some embodiments, a ratio of the inside diameter D2of the pulsation dampener166to a maximum deflection distance of the dampener spring338is between about 1:1 and about 1:3. In some embodiments, the ratio of the inside diameter D2of the pulsation dampener166to a deflection distance of the dampener spring338is about 1:0.8, about 1:1.2, about 1:1.5, about 1:1.8, about 1:2.0, about 1:2.3, about 1:2.6, about 1:2.8, about 1:3.0, about 1:3.3, or about 1:3.5. Further, the inside diameter D2of the pulsation dampener166may be about 30% of the maximum deflection distance of the dampener spring338. In some embodiments, the inside diameter D2of the pulsation dampener166is about 25%, about 35%, about 40%, about 45%, about 50%, about 60%, about 70%, about 85%, or about 100% of the maximum deflection distance of the dampener spring338. The aforementioned relationships between the inside diameter D2of the pulsation dampener166and the maximum deflection distance of the dampener spring338may also be applicable to an average deflection distance of the dampener spring338. The average deflection distance of the dampener spring338may be an average for a duration of time. Further, the average deflection distance of the dampener spring338may be an average during steady state.

Referring again toFIG.11, the pulsation dampener166of the pump assembly142is configured to provide a more continuous pressure behind the nozzle134and, accordingly, a continuous flow of fluid out of the nozzle134. The dampener housing334may define an opening350that is disposed proximate the pump outlet254and is in fluid communication with the discharge conduit250of the pump assembly142. Therefore, instead of traveling from the outlet254of the pump162directly through the discharge conduit250to the nozzle134, fluid may access the pulsation dampener166through the opening350that is in fluid communication with the discharge conduit250. The dampener piston330may have an O-ring354disposed therearound to create a liquid-tight seal within the dampener housing334, thereby isolating the variable volume headspace342from a spring region358that holds the spring338. The spring region358contains a dampener piston shaft362and the spring338and is configured to hold a gas, such as, e.g., air, whereas the variable volume headspace342is configured to hold the fluid that is being dispensed.

Generally, the dampener piston330is configured to linearly translate to accommodate and reduce pressure changes within the nozzle134. For example, as the fluid travels from the outlet254of the pump162, the pressure against the nozzle134may naturally increase. In response, the fluid may provide pressure onto the dampener piston330, thereby causing the dampener piston330to linearly translate toward a compressed configuration in which the dampener spring338is compressed. In the compressed configuration, the air that is held within the spring region358is vented out of the dampener housing334as the piston242moves to increase the volume of the headspace342, thereby reducing the pressure normally experienced during a discharge step of a conventional pump. Correspondingly, during the subsequent intake step of the pump162, as the pressure within the nozzle begins to reduce, the dampener piston330may linearly translate again to decompress the spring338, drawing air back into the spring region358. Consequently, the internal volume within the variable volume headspace342is reduced, which mitigates a significant pressure drop during the intake cycle. As a result, the dampener piston330linearly translates to compress and decompress the spring338within the spring region358and respectively increase and decrease the volume of the headspace342, which results in reduced pressure fluctuations within the discharge conduit250and against nozzle134. Consequently, fluid is dispensed through the nozzle134at a substantially consistent fluid flow rate.

Referring toFIG.14, when the trigger190is depressed, the motor150causes piston242to reciprocate in the pump chamber246, and the pump suction draws a mixture of the diluent and chemical into the pump chamber246. The pump suction draws fluid from an attached container, such as the diluent reservoir106and/or the chemical concentrate container108shown inFIG.2. The pump162expels the fluid into the discharge conduit250which is in fluid communication with the opening350of the pulsation dampener166and the nozzle134for spraying the fluid. Referring again toFIG.13, the fluid may flow either through the nozzle134or through the opening350into the pulsation dampener166. As fluid is discharging from the pump162, pressure within the discharge conduit250may increase, and the fluid within the pulsation dampener166may provide a force on the pulsation dampener piston330, causing the dampener piston330to linearly move, thereby compressing the dampener spring338and increasing the volume of the variable volume headspace342. Simultaneously, fluid may be discharging through the nozzle134. As the nozzle134is undergoing its intake step, the dampener piston330reduces the volume of the variable volume headspace342to minimize pressure fluctuations on the nozzle134and mitigate fluid flow reduction through the nozzle134.

FIGS.16-26provide a series of graphs that demonstrate how a pulsation dampener, such as the pulsation dampener166ofFIG.5, may affect the performance of a dispenser. With reference toFIG.16, a flow rate in meters per second (“m/s”) of a fluid being dispensed by a dispenser is graphed for a duration of time at three locations. For example, a flow rate out of the fluid exiting the pump is shown. The flow rate out of the pump generally oscillates between an intake step370and a discharge step374such that the flow rate gradually increases before rising sharply and then leveling at a maximum flow rate, e.g., about 5.0 m/s in the present example. Subsequently, the flow rate decreases in an opposing manner, i.e., gradually decreasing before decreasing sharply, and then gradually leveling at a minimum flow rate, e.g., about 0 m/s. The flow rate out of the pump generally follows this trend of oscillating between the maximum flow rate and the minimum flow rate.

While the maximum flow rate in the embodiment illustrated is about 5.0 m/s, the maximum flow rate may be about 2.0 m/s, about 4.0 m/s, about 6.0 m/s, about 8.0 m/s, between about 1.5 m/s and about 4.5 m/s, between about 2.0 m/s and about 6.0 m/s, at least 1.0 m/s, or at least 1.8 m/s, for example. A flow rate of the fluid to the pulsation dampener is shown in connection with the flow rate out of the pump. As the pump cycles through the intake step370and the discharge step374, portions of the fluid may be exchanged between the pulsation dampener and the pump to reduce pressure fluctuations within the system and against the nozzle. For example, during the intake step370of the pump, the pulsation dampener is generally feeding the nozzle, which is shown by a negative flow rate to the pulsation dampener.

During the discharge step374of the pump, the pump162feeds the pulsation dampener, which is shown by a positive flow rate to the pulsation dampener. The flow rate to the pulsation dampener generally oscillates at a rate that substantially corresponds to the oscillation of the flow rate out of the pump. Generally, the change in flow rate out of the pump Δpump,out, i.e., 5 m/s in the embodiment illustrated, may substantially equate to the change in flow rate to the pulsation dampener Δdampener. Thus, in the illustrated embodiment, the flow rate to the pulsation dampener oscillates between a maximum of about +2.5 m/s and a minimum of about −2.5 m/s. Although the flow rate to the pulsation dampener in the present embodiment oscillates between the maximum of about +2.5 m/s and the minimum of about −2.5 m/s, minimum and maximum flow rates may vary in different embodiments. For example, in some embodiments the fluid flow rate to the pulsation dampener may oscillate between about +3.0 m/s and about −3.0 m/s, between about +2.0 m/s and about −2.0 m/s, or between about +1.5 m/s and about −1.5 m/s.

Still referring toFIG.16, a combination of the flow rate trends experienced by the pump and the pulsation dampener may result in a substantially steady flow rate out of the nozzle. The flow rate out of the nozzle in the embodiment illustrated generally oscillates between about 2.0 m/s and about 3.0 m/s. Thus, in the present embodiments, a variance in flow rate out of the nozzle, i.e., Δnozzle, is no greater than about 40% of its maximum flow rate. In some embodiments, the flow rate variance Δnozzlemay be less than about 50%, about 35%, about 30%, about 25%, or about 15% of the maximum flow rate. This trend is a result of the pulsation dampener accommodating the increase in flow rate out of the pump and, correspondingly, mitigating a significant increase in pressure by feeding the pulsation dampener. Furthermore, a maximum flow rate out of the nozzle may be no greater than about 60%, about 65%, about 70%, about 75%, or about 80% of the maximum flow rate out of the pump, and a minimum flow rate out of the nozzle may be no less than about 30%, about 35%, about 40%, or about 45% of the maximum flow rate out of the pump.

FIGS.17and18illustrate another example of performance metrics of a fluid application system. Referring particularly toFIG.17, a maximum flow rate out of the pump is about 8 m/s. Thus, the flow rate out of the pump oscillates between the maximum of about 8.0 m/s and a minimum of about 0.0 m/s. Correspondingly, the flow rate to the pulsation dampener oscillates between a maximum of about +4.0 m/s and a minimum of about −4.0 m/s. A flow rate of the resulting fluid flow through the nozzle varies between about 3.6 m/s and about 4.4 m/s. Thus, a variance in flow rate through the nozzle, i.e., Δnozzle, in the embodiment illustrated is about 10% of the maximum flow rate out of the pump. It may take a minimum amount of time, i.e., τsteady, before the flow rate through the nozzle reaches steady state. For example, in the embodiment illustrated, it takes about 0.5 seconds until the fluid flow through the nozzle reaches steady state. In some embodiments, it may take between about 0.1 and about 0.3 seconds, about 0.2 and about 0.4 seconds, about 0.3 and about 0.5 seconds, or about 0.4 and about 1.0 seconds.

FIG.18illustrates a displacement of a dampener piston of the pulsation dampener, which may be substantially similar to the dampener piston330shown inFIG.13. Similar to the flow rate through the nozzle shown inFIG.19, the displacement of the dampener piston also requires an amount of time, i.e., τsteady, before it reaches steady state. In the illustrated embodiment, it takes about 1.4 seconds before the dampener piston reaches steady state. In some embodiments, the dampener piston may reach steady state after about 0.8 seconds, about 1.2 seconds, about 1.6 seconds, or about 2.0 seconds. In some embodiments, it may take no longer than about 1.0 seconds, about 1.5 second, about 2.0 seconds, or about 2.5 seconds for the dampener piston to reach steady state.

Once at steady state, the dampener piston oscillates between a maximum dampener piston displacement of about 5 mm and a minimum of about 3.2 mm. In some embodiments, the maximum may be between about 2 mm and about 7 mm, between about 2.5 mm and about 5 mm, or between about 3.5 mm and about 6 mm. The minimum may be between about 0.5 mm and about 5 mm, between about 1 mm and about 4.5 mm, or between about 3 mm and about 4 mm. A deflection distance of the spring, i.e., Δspring, may be related to the inside diameter of the pulsation dampener. For example, a ratio of the inside diameter of the pulsation dampener housing, e.g., diameter D2inFIG.13, to the deflection distance, i.e., Δspring, may be in a range of between 1:1 and about 1:3. In some embodiments, the ratio may be between about 1:0.7 and about 1:5.

FIGS.19-22illustrate how reducing the inside diameter of a pulsation dampener and, accordingly, reducing a ratio of the pulsation dampener inside diameter to the pump inside diameter may affect the performance of a dispenser. Referring specifically toFIGS.19and20, in connection with a pulsation dampener having a relatively smaller inside diameter, various nozzle and pulsation dampener pressures and flow rates are illustrated over time. Generally, pulsation dampeners having relatively smaller inside diameters and diameter ratios cannot deliver enough fluid to maintain a constant flow rate through the nozzle, which results in the flow rate shown inFIG.19. Further, pulsation dampeners with relatively smaller diameters have less piston surface area, and, thus, lower force against the pulsation dampener spring.

Therefore, a lower spring rate may be required to allow the reduced force against the pulsation dampener spring to overcome the spring force. However, if the spring rate is too low, it may be insufficient for dispensing the fluid through the nozzle, resulting in an unsteady, discontinuous flow. As shown inFIG.19, rather than a continuous, steady-state flow rate, such as the flow rate through the nozzle shown inFIG.16, the flow rate through the nozzle in the present embodiment irregularly varies from a minimum of about 0 m/s to a maximum of about 4.0 m/s. Pressures at the nozzle and the pulsation dampener follow this irregular trend. Thus, a fluid flow with this flow rate would not qualify as steady state.

Similarly,FIGS.23-26illustrate how increasing the inside diameter of a pulsation dampener and, correspondingly, increasing the inside diameter ratio may have adverse effects on the performance of a dispenser. At higher pulsation dampener diameters and higher ratios, the time to reach steady state may be increased because the volumes of the pump and the pulsation dampener are larger. Thus, the pump and pulsation dampener can hold more fluid and require more cycles to reach steady state. For example, as shown inFIG.23, pressure and flow rate through the nozzle has yet to reach steady state after four seconds.

Referring now toFIG.24, the pressure and flow rate at the pulsation dampener fails to reach steady state after four seconds.FIGS.25and26further illustrate the fluid application system's failure to achieve steady state. More specifically, inFIG.25, although the flow rate out of the pump oscillates regularly between about 0 m/s and about 5 m/s, because the flow rate to the pulsation dampener fails to reach steady state, the flow rate through the nozzle continues to gradually increase.FIG.26illustrates the displacement of the pulsation dampener piston over time, which gradually increases over the four second time interval. Additionally, sprayer assemblies having pulsation dampeners with large diameters may experience greater trigger release lag. More specifically, because the pulsation dampener can hold excess fluid, the fluid may continue to discharge through the nozzle after the trigger is released and the pump stops. Also, due to size constraints, pulsation dampeners with large diameters may be generally undesirable.

INDUSTRIAL APPLICABILITY

Numerous modifications will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the embodiments disclosed herein. The exclusive rights to all modifications which come within the scope of the application are reserved.