The present invention is related to handheld sprayers, and in particular to systems and methods for controlling airflow for integrated handheld sprayers.
Handheld texture sprayers are utilized, for example, to apply coatings to walls, ceilings, and/or other surfaces. These coatings may include, for example, “knockdown” finishes, “popcorn” finishes, and fine “orange peel” finishes. Texture sprayers are supplied a viscous material, such as, for example, drywall mud from a separate tank or an attached hopper. An airflow provided to the sprayer atomizes the fluid into a spray that is applied to a surface in order to create a desired finish.
In the past, the airflow has been provided from, for example, an external air compressor. These air compressors are often bulky and limit the mobility and convenience of the texture sprayer. To provide portability, these external air compressors have been replaced with a local airflow source, such as a turbine. One such portable texture sprayer is disclosed in U.S. Pat. No. 7,731,104. While providing portability, these texture sprayers lack the control desirable for providing specific and quality texture finishes. These texture sprayers are limited in both the type and quality of finish they can provide. It is desirable to provide improved control for handheld sprayers in order to provide a greater range and greater quality of the finishes created by the sprayer.
A handheld sprayer comprises a housing, a turbine, a spray tip, a hopper and a trigger. An air flow passage extends through the housing. The turbine is configured to generate an airflow within the air flow passage. The spray tip is positioned to receive airflow from the air flow passage. The hopper is connected to the housing and is configured to discharge a fluid into the air flow passage. The trigger is mounted to the housing to control discharge of the hopper into the flow passage and airflow form the turbine. In different embodiments, the trigger controls airflow from the turbine to the spray tip or the hopper or both.
A method for spraying a fluid from a handheld sprayer comprises generating an airflow with a turbine, directing the airflow through a passage within the sprayer to a spray tip, selectively discharging a fluid into the passage from a hopper for spraying through the spray tip, and controlling airflow from the turbine using a combined actuator that also controls discharge of the hopper into the passage.
Disclosed herein is a handheld texture sprayer that includes a combined actuator for controlling flow of air from a turbine and flow of fluid from a hopper into a flow passage. The handheld texture sprayer includes a housing, a turbine, a spray tip, and a hopper. An air flow passage extends through the housing and carries an airflow generated by the turbine. The hopper is connected to the housing and holds fluid that is provided to the airflow passage for spraying. The sprayed fluid is projected through the spray tip for application to a surface. In one embodiment, the combined actuator controls airflow from the turbine to the spray tip. In another embodiment, a bleed line connects an output of the turbine to the hopper, the hopper includes a sealable lid, and the combined actuator controls airflow from the turbine to the hopper to pressurize the hopper.
Turbine 12 utilizes electrical power from cord 18 to generate a flow of compressed air for pushing liquid from hopper 16 through dispenser 14. Turbine 12 is inserted into housing 20 of dispenser 14 to fluidly interact with spray tip 22. Housing 20 includes handle 24 into which is integrated trigger 26. An operator of sprayer 10 grasps handle 24 with a hand while resting a forearm on pad 28 so that trigger 26 can be actuated with one or more fingers. Turbine 12 is activated via a power switch (
As will be discussed in more detail with reference to
Turbine 12 pushes air into plenum 38 at turbine outlet 44. Piston 40 guides air from plenum 40 to spray tip 22. Spray tip 22 and piston 40 operate as a valve to control flow of fluid from hopper 16 into spray tip 22. Spray tip 22 and piston seal against each other when engaged in a closed position to prevent air from being in fluid communication with mix chamber 30. Spring 57 pushes between flange 56 and plenum 38 to bias piston 40 to the closed position. In order to move piston 40 to an open position, trigger 26 is translated, such as by an operator of sprayer 10, away from spray tip 22 (to the right in
Moving piston 40 from the closed position to the open position opens the valve formed by spray tip 22 and piston 40, and allows fluid from within hopper 16 that is present within mix chamber 30 to enter the air flow path between spray tip 22 and piston 40. In one embodiment, the fluid is pushed into the air flow path primarily via gravity. Additionally, the flow of compressed air between piston 40 and spray tip 22 generates a slight vacuum that pulls in fluid from hopper 16. As such, the flow of air through piston 40 pulls the fluid along through spray tip 22.
The pattern of the sprayed fluid can be adjusted by changing the amount that trigger 26 is actuated. Retracting trigger 26 further into handle 24 allows for more fluid to enter spray tip 22, thereby resulting in a more dense spray pattern. Trigger lock 58 is adjustable to limit the movement of trigger 26. For example, trigger lock 58 can be locked into different positions along the top of handle 24 to provide a barrier to translation of trigger 26 into handle 24. Trigger lock 58 is provided on handle 24 in a location convenient for an operator of sprayer 12 to access, such as with a thumb. Furthermore, the spray pattern can be adjusted by swapping out spray tip 22 for other spray tips having different sized openings that will widen or narrow the pattern of discharged fluid from sprayer 10.
Integrated handheld texture sprayer 10 of the present invention may include other features not described above or that elaborate on the features described above. For example, the present invention is directed to a combined actuator that simultaneously controls flow of air from turbine 12 and flow of fluid from hopper 16 into the flow passage of sprayer 12. In one embodiment, the combined actuator controls airflow from turbine 12 to spray tip 22. In another embodiment, the combined actuator controls airflow from turbine 12 to hopper 16 in order to pressurize hopper 16.
Turbine 212 provides compressed air to plenum 238, which, through piston 240, feeds spray tip 222. Spring 257 engages flange 256 to bias piston 240 toward spray tip 222. Trigger 226 can be actuated to pull piston 240 away from spray tip 222 via a linkage (not shown) that engages flange 256. Thus, any fluid disposed within mix chamber 230 will be forced through spray tip 222 when piston 240 retracts while turbine 212 is operating. In order to assist with flow of fluid from hopper 216 to spray tip 222, sprayer 210 is provided with an air-assist mechanism that pressurizes the interior of hopper 216.
When powered, turbine 212 continuously provides compressed air to spray tip 222. Bleed line 268 is configured to redirect a portion of the compressed air from plenum 238 to the interior of hopper 216. In one embodiment, bleed line 268 comprises a plurality of segments 268A, 268B and 268C, which may be fabricated from flexible tube or hose, that extends between hopper fitting 270 and plenum fitting 272. Fitting 272 provides a tap-off point from plenum 238 that supplies bleed line 268A with compressed air from turbine 212. In one embodiment, fitting 272 comprises a cylindrical extension from plenum 238 around which bleed line 268 is fitted. Fitting 270 provides a feed point into hopper 216 that receives compressed air from bleed line 268C. In one embodiment, fitting 270 comprises a cylindrical extension from hopper 216 around which bleed line 268 is fitted. In various embodiments, fittings 270 and 272 may be provided with barbs or the like to inhibit dislodgment of bleed line 268 from the fittings.
Bleed line 268B connects bleed line 268A and bleed line 268C using valve 269. Bleed line 268B connects to bleed line 268C through a fitting that allows feed line 268 to extend out of housing 220. Valve 269 directly connects bleed line 268B and bleed line 268A. As such, valve 269 may have fittings or other such fluid couplings to connect with tubes or hoses. Valve 269 is positioned to mechanically engage with trigger 226. Valve 269 can be actuated to open and close airflow through bleed line 268. Specifically, in one embodiment, when trigger 226 is pulled back to allow air from turbine 212 to spray tip 222, valve 269 is also opened.
Compressed air from bleed line 268 is directed into an upper portion of hopper 216 near lid 236. In the depicted embodiment, fitting 270 penetrates into hopper 216 at flange 272. Lid 236 is configured to mate with flange 272 to seal liquid within hopper 216. Lid 236 may be joined to flange 272 via any suitable means, such as a snap fitting or a threaded connection. Compressed air introduced into hopper 216 enters between lid 236 and fluid line FL, thereby pressurizing the interior of hopper 216 and forcing the fluid toward outlet 274 and mix chamber 230.
Pressurization of hopper 216 results in higher and more consistent flow rates between hopper 216 and mix chamber 230. Additionally, the pressurization reduces the potential for pack out, wherein mix chamber 230 becomes clogged with texture material added to the fluid of hopper 216. Pressurization of hopper 216 thus enables spraying of a larger array of materials, with different finishes, textures, mixture rates and viscosities. Additionally, the presence of lid 236, which facilitates generation of the pressurized hopper, also allows for sprayer 210 to be utilized in a wider array of orientations without spilling fluid from hopper 216. The use of an external air supply is eliminated due to the presence of integrated turbine 212.
Bleed valve 269 is positioned in bleed line 268 between fitting 272 and fitting 270. Bleed valve 269 comprises an adjustable valve that can restrict the flow of compressed air bled at fitting 272. For example, bleed valve 269 includes lever 275 that can be actuated as trigger 226 is displaced into handle 224. Lever 275 can be displaced to open and close airflow through bleed line 268. In a fully open position, valve 269 may provide no restriction of airflow. In a fully closed position, valve 269 may close-off all airflow through bleed line 168. Bleed valve 269 can be manually set with trigger 226 to any intermediate position between fully open and fully closed as trigger 226 is actuated. Thus, valve 269 can be used to provide a desired amount of pressurization to hopper 216, based on the amount of pressurized air provided by turbine 212. Bleed valve 269 may comprise any suitable valve as is known in the art.
As described, trigger 226 simultaneously controls valve 269 and the valve formed at the interaction of piston 240 and spray tip 222. Thus, trigger 226 comprises a combined actuator for both the flow of bleed air through bleed line 268 and the flow of fluid from hopper 216. Combining airflow and fluid flow increases the ease of operation for an operator of sprayer 210. Separate adjustments of fluid flow and airflow are avoided and an operator can focus on actuation of only a single control, trigger 226. Thus, better control over the spray pattern from spray tip 222 can be achieved. Furthermore, in other embodiments, valve 269 can be selected to have discharge settings specific for different texture finishes. For example, valve 269 can be set to limit or restrict airflow through bleed line 268 from what might otherwise be available from the bleed point at fitting 272, such as for fluids having low viscosity.
Sprayer 210 of
Valve 278 comprises an adjustable valve that can restrict the flow of compressed air from turbine 212 (
Control of airflow from turbine 212 to spray tip 222 is desirable to allow for better control of texture finishes created by texture sprayer 210. For example, less airflow may be desirable for creating heavy “knockdown” finishes while greater airflow may be desirable for creating fine “orange peel” finishes. Thus, the amount of airflow through valve 278 dictates the texture finish created by the spray produced through spray tip 222. By controlling the airflow from turbine 212 to spray tip 222 while simultaneously controlling fluid flow from hopper 216, better control of the texture finish produced by texture sprayer 210 is accomplished.
Although the present invention has been described with reference to preferred embodiments, workers 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.
Filing Document | Filing Date | Country | Kind |
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PCT/US2014/012963 | 1/24/2014 | WO | 00 |
Number | Date | Country | |
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61756110 | Jan 2013 | US |