Portable airless fluid dispensing apparatus and valve

Abstract

The present disclosure relates to a portable airless fluid dispensing apparatus and a valve, and discloses an airless fluid dispensing apparatus, a stem-less spray valve, and a pressure relief valve. The valve-stem-free spray valve comprises: a substantially cylindrical valve body; a fluid conduit operable to allow fluid to at least partially flow from the pump through the valve body to the spray hole; a movable plug at least partially disposed within the valve body; a seat shaped to coincide with the shape of the movable plug; and the spring is arranged in the valve body. When the fluid pressure is below a spray pressure threshold, the spring biases the movable plug against the seat to prevent fluid flow through the fluid conduit to the spray hole. When the fluid pressure reaches or exceeds a spray pressure threshold, the spring compresses to at least partially retract the movable plug from the seat and allow fluid to flow through the fluid conduit to the spray hole.

Description

Technical Field

[0001] The present disclosure generally relates to fluid dispensing systems, and more particularly to portable airless paint sprayers. Background Art

[0002] Portable airless paint sprayers are ideal tools for hobbyists or do-it-yourselfers to paint surfaces such as furniture, cabinets, decorative fittings, or other architectural structures. Different from expensive and bulky pneumatic paint sprayers that require an air compressor and hoses, airless paint sprayers can finely atomize fluid paint in a compact and easy-to-maneuver package, thus providing a professional-quality paint finish.

[0003] Typical airless paint sprayers operate by pressurizing a fluid (such as paint, varnish, stain, or lacquer) up to and beyond 3000 psi and discharging the pressurized fluid through one or more small shaped orifices. Such airless paint sprayers use an electric motor, a gasoline motor, or an air compressor to pressurize the fluid paint. In larger-scale applications, the power unit is connected to a fixed paint source (such as a 5-gallon bucket), and a hose is used to supply the pressurized paint to the spray gun. For smaller-scale applications, it may be necessary to create a compact paint sprayer that includes an electric motor for pressurizing the paint and an integrated fluid container for holding the fluid paint. Such smaller compact airless paint sprayers can be powered, for example, by a rechargeable 20V battery or alternatively include a power cord to connect to a conventional power outlet.

[0004] Traditional compact airless paint sprayers (including, for example, buzz guns or cup guns) suffer from a lack of performance, resulting in a less professional paint finish, which is at least partially due to the low pressure generated by a smaller electric motor and the low-grade spray nozzles used to accommodate these lower pressures. Therefore, there may be a need to provide a compact handheld airless paint sprayer that can produce a professional-grade paint finish, uses a smaller electric motor, and is powered by a rechargeable battery or a conventional power outlet. Summary of the Invention

[0005] Disclosed is a portable airless paint sprayer that is substantially as illustrated and described by at least one of the accompanying drawings and more fully set forth in the claims.

[0006] Specifically, an embodiment of a stem - less valve for a fluid spraying device is disclosed. The stem - less valve includes: a cylindrical valve body including a sealed end and an open end; a movable plug at least partially disposed within the cylindrical valve body and near the open end; an air chamber disposed between the movable plug and the sealed end of the cylindrical valve body; a seal around the movable plug operable to seal air within the air chamber; a seat shaped to conform to the shape of the movable plug; a spray hole positioned downstream of the seat; a fluid conduit operable to allow fluid to flow at least partially through the cylindrical valve body from a pump to the spray hole positioned downstream of the seat; and a spring disposed within the air chamber. The spring is positioned between the sealed end of the cylindrical valve body and the movable plug. When the fluid pressure is below the spray pressure threshold, the spring biases the movable plug against the seat to prevent fluid from flowing through the fluid conduit to the spray hole. When the fluid pressure reaches or exceeds the spray pressure threshold, the spring compresses, thereby at least partially retracting the movable plug from the seat and allowing fluid to flow through the fluid conduit to the spray hole.

[0007] In another embodiment, the spray pressure threshold is between 800 PSI and 2000 PSI. In a further embodiment, the movable plug includes a cylindrical body and a head coupled to the cylindrical body. In some embodiments, the head of the movable plug has a frustoconical shape. In such embodiments, the cylindrical body of the movable plug includes at least one groove, and the groove is operable to receive at least one seal. In other embodiments, the spring includes a compression spring. In another embodiment, when compressed by the movable plug, the air chamber is operable to act as a damper for the spring to reduce vibration of the spring caused by the operation of the pump or a motor operably connected to the pump. In some embodiments, the spring is isolated from the fluid. In other embodiments, the movable plug further includes a stop operable to prevent the movable plug from retracting from the seat by more than a preferred distance. Finally, in one embodiment, the sealed end includes a threaded plug screwed into the cylindrical valve body.

[0008] Another embodiment of a stem - less valve for a fluid spraying device is also disclosed. The stem - less valve includes: a cylindrical valve body including an upstream end and a downstream end; a fluid conduit operable to allow fluid to flow through the cylindrical valve body from a pump to a spray hole positioned downstream of the cylindrical valve body; a movable plug disposed within the cylindrical valve body; a seat shaped to conform to the shape of the movable plug, the seat being disposed within the cylindrical valve body and adjacent to the upstream end; and a spring disposed within the cylindrical valve body. When the fluid pressure is below the spray pressure threshold, the spring biases the movable plug against the seat to prevent fluid from flowing through the fluid conduit to the spray hole. When the fluid pressure reaches or exceeds the spray pressure threshold, the spring compresses, thereby at least partially retracting the movable plug from the seat and allowing fluid to flow through the fluid conduit to the spray hole.

[0009] In another embodiment, the cylindrical valve body further comprises: a downstream portion including a threaded bore; and a removable upstream portion including threads disposed around the removable upstream portion, wherein: the threads of the removable upstream portion are operable to engage the threaded bore of the downstream portion to fasten the removable upstream portion to the downstream portion, thereby holding the spring and the movable plug within the cylindrical valve body. In some embodiments, the spray pressure threshold is between 800 PSI and 2000 PSI. In other embodiments, the spring includes a compression spring.

[0010] An embodiment of a handheld fluid dispensing device is also disclosed. The handheld fluid dispensing device includes: a housing including a handle; an electric motor positioned within the housing and operable to output a rotational motion; a driver positioned within the housing and operably coupled to the electric motor, the driver being operable to convert the rotational motion into a reciprocating linear motion; an actuator disposed on the housing and adjacent to the handle, the actuator being operable to actuate the electric motor; a fluid container mounted to the housing and operable to receive and hold fluid; and a pump positioned within the housing and operably coupled to the driver, the pump being operable to draw fluid from the fluid container, pressurize the fluid, and drive the fluid through a valveless stem type valve to a spray orifice positioned downstream of the valveless stem type valve. The valveless stem type valve includes: a valve body that is generally cylindrical; a fluid conduit operable to allow fluid to flow at least partially through the valve body from the pump to the spray orifice; a movable plug at least partially disposed within the valve body; a seat shaped to conform to the shape of the movable plug; and a spring disposed within the valve body. When the fluid pressure is below the spray pressure threshold, the spring biases the movable plug against the seat to prevent fluid from flowing through the fluid conduit to the spray orifice. When the fluid pressure reaches or exceeds the spray pressure threshold, the spring compresses, thereby at least partially retracting the movable plug from the seat and allowing fluid to flow through the fluid conduit to the spray orifice.

[0011] In another embodiment, a nozzle guard is mounted to the housing; the nozzle guard includes an aperture; and a reversible nozzle including a barrel. The barrel is insertable into the aperture of the nozzle guard and rotatable within the aperture; and the spray orifice is disposed within the barrel. In some embodiments, the spray pressure threshold is between 800 PSI and 2000 PSI. In other embodiments, the spring includes a compression spring. In another embodiment, the valve body further includes an open end and a sealed end; and the movable plug further includes a cylindrical body, a head, and at least one seal disposed around the cylindrical body; wherein: the cylindrical body of the movable plug encloses an air cavity between the movable plug and the sealed end of the cylindrical valve body; and the at least one seal is operable to seal air within the air cavity. In a further embodiment, the head of the movable plug has a frustoconical shape.

[0012] Another embodiment of a handheld fluid dispensing device is also disclosed. The handheld fluid dispensing device includes: a housing that includes a handle; an electric motor positioned within the housing and operable to output a rotational motion; a driver positioned within the housing and operably coupled to the electric motor, the driver operable to convert the rotational motion into a reciprocating linear motion; an actuator disposed on the housing and adjacent to the handle, the actuator operable to actuate the electric motor; a fluid container mounted to the housing, the fluid container operable to receive and hold fluid; a pump positioned within the housing and operably coupled to the driver, the pump operable to draw fluid from the fluid container, pressurize the fluid, and drive the fluid downstream of the pump to atomize the fluid; a pressure relief valve connected to the pump and positioned downstream thereof, the pressure relief valve operable to activate the pump and redirect the fluid back to the fluid container when the fluid pressure output by the pump exceeds a pressure relief threshold; a spray valve connected to and positioned downstream of the pressure relief valve; and a nozzle assembly connected to and positioned downstream of the spray valve, the nozzle assembly including spray holes operable to atomize the fluid.

[0013] In such an embodiment, the spray valve includes: a valve body that is generally cylindrical; a fluid conduit operable to allow fluid to flow at least partially through the valve body from the pressure relief valve to the spray holes of the nozzle assembly; a frustoconical plug disposed at an end of a valve stem, wherein the frustoconical plug and the valve stem are fully positioned within the valve body; a seat shaped to conform to the shape of the frustoconical plug; and a spring disposed around the valve stem and positioned within the valve body. When the fluid pressure is below a spray pressure threshold, the spring biases the frustoconical plug against the seat to prevent fluid from flowing through the fluid conduit to the spray holes. When the fluid pressure reaches or exceeds the spray pressure threshold, the spring compresses, thereby at least partially retracting the frustoconical plug and the valve stem from the seat and allowing fluid to flow through the fluid conduit to the spray holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following is a brief description of the drawings associated with the present disclosure, which will be discussed in more detail in the Detailed Description section below.

[0015] Figure 1 A block diagram and profile of an airless fluid dispensing device and its core components are illustrated.

[0016] Figure 2 An assembled perspective view of the airless fluid dispensing device is illustrated.

[0017] Figure 3 An exploded perspective view of the airless fluid dispensing device, which includes a spray valve and a pressure relief valve, is illustrated.

[0018] Figure 4 Illustrated is Figure 3 A partial cross-sectional view taken along the X-Y plane of an embodiment of the spray valve shown in

[0019] Figure 5 Illustrates Figure 3 A partial cross-sectional view taken along the X-Y plane of another embodiment of the spray valve shown in

[0020] Figure 6 Illustrates Figure 3 A partial cross-sectional view taken along the X-Y plane of another embodiment of the spray valve shown in

[0021] Figure 7 Illustrates Figure 3 A partial cross-sectional view taken along the Z-Y plane of one embodiment of the pressure relief valve shown in

[0022] Figure 8 Illustrates Figure 3 A partial cross-sectional view taken along the Z-Y plane of another embodiment of the pressure relief valve shown in

[0023] Figure 9 Illustrates Figure 3 A partial cross-sectional view taken along the Z-Y plane of another embodiment of the pressure relief valve shown in

[0024] When read in conjunction with the accompanying drawings, the foregoing summary of the invention and the following detailed description of certain features of the present application are better understood. For purposes of illustration, certain features are shown in the drawings. However, it is to be understood that the claims are not limited to the arrangements shown in the drawings. Although specific features of various embodiments may be shown in some drawings and not in others, this is merely for convenience. Any feature of any drawing may be cited and / or claimed in combination with any feature of any other drawing.

[0025] Unless otherwise indicated, the drawings provided herein are intended to illustrate the features of embodiments of the present disclosure. These features are believed to be applicable in a wide variety of applications including one or more embodiments of the present disclosure. Thus, the drawings are not intended to include all conventional features known to those of ordinary skill in the art that are required for the practice of the embodiments disclosed herein. Detailed Description

[0026] Figure 1The figure illustrates an example block diagram of a portable airless fluid dispensing device 1 (“the device”). As shown in the illustrated embodiment, the device 1 generally includes a compact portable airless spray gun and includes a housing 10, a nozzle assembly 20, a spray valve 100, a pressure relief valve 200, a pumping mechanism 30, a motor 40, and a fluid container 50. The pumping mechanism 30 may include, for example, a gear pump, a piston pump, a plunger pump, a vane pump, a rolling diaphragm pump, a ball pump, a rotary cam pump, a diaphragm pump, or a servo motor with a rack and pinion drive. The motor 40 may include, for example, an electric motor, an air-driven motor, a linear actuator, or a gasoline engine.

[0027] The spray valve 100, the pressure relief valve 200, the pumping mechanism 30, and the motor 40 are each at least partially contained within and encapsulated by the housing 10. The nozzle assembly 20 is removably connected to the spray valve 100 to facilitate maintenance and cleaning. Similarly, the fluid container 50 is removably connected to the housing 10 such that it can be easily removed to fill the paint or other fluid to be dispensed by the device 1. As Figure 1 shown, the device is compact because each of the nozzle assembly 20, the spray valve 100, the pressure relief valve 200, the pumping mechanism 30, the motor 40, and the fluid container 50 is either encapsulated within the housing 10 or connected to the housing. In an alternative embodiment (not shown), the fluid container 50 may be separated from the housing 10. In such embodiments, the fluid container 50 may be operably connected to the nozzle assembly 20, the spray valve 100, the pressure relief valve 200, the pumping mechanism 30, and the motor 40 via a hose (not shown). Further, in another alternative embodiment (not shown), the nozzle assembly 20 and the spray valve 100 may be detached from the housing 10. In such embodiments, the nozzle assembly 20 and the spray valve 100 are operably connected to the pressure relief valve 200, the pumping mechanism 30, the motor 40, and the fluid container 50 via a hose (not shown).

[0028] Regardless of which configuration is utilized, the portable airless fluid dispensing device 1 generally operates as follows. The fluid contained within the fluid container 50 is drawn into the pumping mechanism 30 and pressurized within the pumping mechanism 30 using the power from the motor 40. The pressurized fluid then flows through the pressure relief valve 200 to the spray valve 100. Once a sufficient spray pressure threshold has been reached, the spray valve 100 opens and allows the pressurized fluid to pass through to the nozzle assembly 20 and specifically through to the spray orifice (not shown), which atomizes the fluid as it exits the nozzle assembly 20. An example spray orifice ideally has an area between 0.001 and 0.05 square inches and is operable to atomize a fluid (e.g., paint, varnish, stain, or lacquer) to approximately 150 microns or less. For example, in operation, the pumping mechanism 30 driven by the motor 40 can generate a spray pressure threshold of approximately 800 - 1500 psi. However, it should be understood that depending on the power of the motor 40, lower or higher spray pressure thresholds can be achieved. For example, in an example of a larger form factor, a spray pressure threshold of approximately 1000 to 3000 PSI may be required. When the fluid pressure exceeds the spray pressure threshold, if the fluid pressure has reached the pressure relief threshold, the pressure relief valve 200 is operable to release some of the pressurized fluid back into the fluid container 50. A typical pressure relief threshold is 2500 - 3000 PSI, but it may be higher, depending on the size of the device 1 and the spray pressure threshold. Similarly, the pressure relief valve 200 is operable to expose the pump 30 to atmospheric pressure in order to prime the pump 30.

[0029] Figures 2 - 3 An exploded and assembled example of the airless fluid dispensing device 1 is illustrated. As illustrated, the device 1 includes a nozzle assembly 20, a pumping mechanism 30, and a motor 40 disposed within a housing 10. Located between and connected to the nozzle assembly 20 and the pumping mechanism 30 are a spray valve 100 and a pressure relief valve 200. The example device 1 further includes a trigger 11, an integrated handle 12, and a power source (not shown), each of which is integrated into the housing 10 or operably coupled to the housing. The device 1 may additionally include a start switch 17 and a pressure selector 18. The power source includes an electrical system for providing power to the motor 40. The power source can be, for example, a rechargeable battery or a power cord plugged into a conventional outlet. The fluid container 50 is operably coupled to a housing thread integrated with the housing 10. The pressure relief valve 200 is operably coupled to the pumping mechanism 30 and is operable to open the pumping mechanism 30 to atmospheric pressure. Further, as illustrated, the nozzle assembly 20 includes a nozzle 21, a connector 22, and a nozzle guard 21. The nozzle guard 21 is connected to the connector 22 to prevent any object from interfering with or contacting the high-speed fluid output from the nozzle 21.

[0030] The fluid container 50 contains any fluid suitable for atomizing and spraying by the device 1 (e.g., paint, varnish, colorant, lacquer, etc.). The fluid container 50 is operatively coupled to the remainder of the device 1 and, in particular, is operatively coupled to the pumping mechanism 30 and the nozzle assembly 20. In one example, the trigger 11 is operatively connected to the power source 13 and the motor 40 such that when the trigger 11 is actuated, the power from the power source 13 activates the motor 40. The motor 40, in turn, provides a power input into the pumping mechanism 30, which draws fluid from the fluid container 50 via the straw 51. Specifically, the motor 40 is operatively coupled to the pumping mechanism 30 via the connecting assembly 41 and the gear assembly 42. The pumping mechanism 30 pressurizes the fluid and forces the pressurized fluid through the nozzle assembly 20.

[0031] As Figures 4 - 6 shown, the nozzle assembly 20 includes a nozzle guard 21, a connector 22, and a hole 23 for inserting the nozzle 24. The nozzle 24 includes a barrel 25, spray holes 26 disposed within the barrel 25, and a spray marking 27. Further, the saddle seal 28 is operable to seal the barrel 25 against the spray valve 100, thereby ensuring that no fluid escapes from the fluid conduit 101. As illustrated, the connector 22 operatively couples the nozzle assembly 20 to the device 1 via the spray valve threads 29, which engage corresponding nozzle guard threads 109 on the spray valve 100. The nozzle 24 is inserted through the hole 23. Specifically, the barrel 25 of the nozzle 24 is inserted through and into the hole 23. In one example, the barrel 25 includes a removable nozzle or a reversible nozzle that rotates within the nozzle guard 21. The spray holes 26 receive the forced flow of pressurized fluid (at the spray pressure threshold) from the pumping mechanism 30. The pressurized fluid is atomized as it is forced through the spray holes 26. The spray marking 27 is operable to indicate the spray direction of the fluid.

[0032] The device 1 may further include a circuit board (not shown) that is operable to control the motor 40. For example, the circuit board may be programmed to change the current and / or voltage supplied to the drive motor 40 to change the flow rate from the pumping mechanism 30. Similarly, the circuit board may be programmed to use pulse width modulation (PWM) to slow the output of the motor 40 when drawing high current from the power source. Additionally, the circuit board may include a temperature sensor 16 that is operable to monitor the temperature of the motor 40 and / or the power source.

[0033] It can be operated as follows Figure 2 and Figure 3The device 1 depicted therein. The operator fills the fluid container 50 with a fluid (e.g., paint), which the operator intends to spray onto a workpiece. The operator actuates the trigger 11, which in turn activates the motor 40. The motor 40 rotates the drive shaft 43 while drawing power from the power supply 13. The drive shaft is connected to the gear 42. The gear 42 then actuates the connecting assembly 41 to actuate the pumping mechanism 30. The pumping mechanism 30 sucks the fluid from the fluid container 50 using the straw 51. In one example, the excess fluid that the pumping mechanism 30 cannot handle (pressurize) flows back to the fluid container 50 through the pressure relief valve 200 and the return line 32 (as shown in Figures 7 - 9 ) shown. The pressurized fluid from the pumping mechanism 30 flows through the pressure relief valve 200 to the spray valve 100. Once the fluid pressure reaches or exceeds the spray pressure threshold, the spray valve 100 opens to allow the pressurized fluid to enter the barrel 25 of the nozzle 21, which includes the spray holes 26. Then, the pressurized fluid is forced through the spray holes 26, which atomize the fluid as it exits the device 1. If the fluid pressure reaches or exceeds the pressure relief threshold, the pressure relief valve 200 opens to allow some or all of the pressurized fluid to flow back to the fluid container 50.

[0034] Figures 4 - 6 is shown Figure 3 A cross-sectional view taken along the X-Y plane of a different embodiment of the spray valve 100 shown in Figure 4 and Figure 5 ). The spray valve 100 can be a valve stemless type valve ( Figure 6 ) or a valve stem type valve (

[0035] Figures 4 - 6 ). As illustrated, the spray valve 100 includes a fluid conduit 101, an outer wall 102, a pressure relief valve thread 108, and a nozzle guard thread 109. The spray valve 100 is attached to the pressure relief valve 200 by engaging the pressure relief valve thread 108 with the corresponding spray valve thread 208 on the pressure relief valve 200. Similarly, the nozzle assembly 20 is attached to the spray valve 100 by engaging the spray valve thread 29 of the nozzle assembly 20 with the corresponding nozzle guard thread 109 of the spray valve 100. Each of the spray valves 100 shown in Figures 4 - 6The valve shown in [description] includes different internal structures for mounting, securing, and positioning the movable plug 120, seat 130, and spring 140. However, the function of each of the spray valves 100 is generally as follows.

[0036] The spring 140 biases the movable plug 120 towards the seat 130. The movable plug 120 and the seat 130 are positioned in line with the fluid conduit 101 such that when the movable plug 120 is seated on the seat 130, the fluid conduit 101 is blocked and fluid cannot pass through the movable plug 120. Thus, when the device 1 is closed or when the fluid pressure of the fluid is below the spray pressure threshold, the movable plug 120 is seated on the seat 130 in the closed position and fluid cannot pass through the fluid conduit 101. When the device 1 is activated by actuating the trigger 11 (as described above), the pumping mechanism 30 draws fluid from the fluid container 50 and begins to pressurize the fluid. When the fluid pressure of the fluid within the fluid conduit 101 reaches the spray pressure threshold (which is related to the force required to compress or deform the spring 140), the movable plug 120 retracts and / or separates from the seat 130 in the open position. At this time, fluid can pass through the fluid conduit 101 to reach the nozzle 24 (and the spray orifice 26). It should be understood that the spray pressure threshold can be increased or decreased by adjusting the spring rate of the spring 140. For example, replacing the spring 140 with a different spring having a lower or greater spring rate (i.e., the force exerted by the spring as calculated by Hooke's Law) may cause the spray pressure threshold to change.

[0037] As Figures 4 - 6 As illustrated, the valve body 110 includes a flange 115 at the downstream end of the valve body 110. Further as illustrated, the outer diameter of the valve body 110 is less than the inner diameter of the outer wall 102 such that there is a cavity (i.e., the fluid conduit 101) between the valve body 100 and the outer wall 102. The valve body 110 may also include one or more seals 103 (e.g., O-rings positioned in grooves) to prevent fluid leakage when the valve body 110 is installed in the spray valve 100. The valve body 110 is attached to the outer wall 102 (and thus to the device 1) by inserting the valve body 110 into the cylinder formed by the outer wall 102 until the flange 115 contacts the outer wall 102. When the nozzle assembly 20 is attached to the spray valve 100 (as described above), the valve body 110 is clamped between the nozzle assembly 20 (specifically, the saddle seal 28) and the outer wall 102.

[0038] The spray valve 100 may further include an anchoring portion 105 positioned generally upstream of the valve body 110. The anchoring portion 105 may be integral with the outer wall 102 (i.e., machined from a single piece of material) or fastened within the outer wall 102. The anchoring portion 105 may be operative to provide a fixed anchoring position for one or more springs 140 or 240. The valve body 110 and the outer wall 102 of the spray valve 100 may be machined metal (e.g., aluminum or stainless steel) or any other suitable material capable of withstanding fluid pressure.

[0039] Figure 4 Specifically shown is a valveless spray valve 100 that includes a multi-piece movable plug 120 and an air chamber 113 within the valve body 110. Also shown is a seat 130 that is integral with the valve body 110 and is shaped to conform to the shape of the movable plug 120. Specifically, the movable plug 120 includes a cylindrical body 121 and a head 122. As illustrated, the head 122 has a frustoconical shape, but other shapes are possible (e.g., conical, dome shape, pyramid shape, etc.). The head 122 may be made of any suitable material (e.g., carbide, tungsten, ultra-high molecular weight polyethylene (“UPE”), polyurethane (“PU”), etc.) capable of providing a secure seal against the seat 130. As illustrated, the valve body 110 includes a sealed end 111 (sealed by a threaded plug 114) and an open end 112 (i.e., the fluid conduit 101). The movable plug 120 further includes one or more seals 103 (e.g., O-rings) positioned within a groove 123 around the movable plug 120. The (multiple) seals 103 seal air within the air chamber 113 disposed between the movable plug 120 and the sealed end 111 of the valve body 110 (specifically, the threaded plug 114). The sealed end 111 acts as an anchor for the spring 140 and a stop 141 for biasing the movable plug 120, which is operative to limit the retraction of the movable plug 120 to a preferred distance to prevent misalignment of the movable plug 120. The air chamber 113 (and the air therein) acts as a damper for the spring 140 when compressed by the movable plug 120 to reduce the vibration of the spring 140 caused by the operation of the pump 31 or a motor 40 operatively connected to the pump 31. Further, the seal 103 isolates the spring 140 from the fluid.

[0040] As Figure 4 illustrated (but also applicable to Figure 5 and Figure 6 ), the movable plug 120 has a vertical or partially vertical surface 125 that is exposed to the fluid cavity 101. The cylindrical body 121 and / or the head 122 of the movable plug 120 must have a sufficient vertical portion 125 for the fluid to push against such that the normal force is generally parallel to the direction of the elastic force of the spring 140.

[0041] For assembly Figure 4For the spray valve 100, first, the movable plug 120 is inserted into the valve body 110 at the downstream end. Second, the spring 140 is inserted into the valve body 110 at the downstream end. Third, the threaded plug 114 is screwed onto the corresponding thread of the valve body 110. The threaded plug 114 is operable to adjust the spring load of the spring 140 and the spray pressure threshold (i.e., the cracking pressure threshold). For example, in the case of screwing the threaded plug 114 into or out of the valve body 110, the spring load increases or decreases. More specifically, the more the threaded plug 114 is screwed into the valve body 110, the greater the spring load on the spring 140, and the less the threaded plug 114 is screwed into the valve body 110, the smaller the spring load on the spring 140. Having the ability to adjust the spring load as described has certain manufacturing benefits. For example, the manufacturer has the ability to finely tune the spray pressure threshold. Further, the material tolerance of the spring 140 can be reduced, resulting in cost savings. Fourth, as described above, the valve body 110 is coupled to the outer wall 102 and the nozzle assembly 20. Finally, easy assembly also allows for easy disassembly, which is essential for proper cleaning and maintenance of the device 1.

[0042] Figure 5 Another embodiment of the valveless spray valve 100 is shown. The spring 140 is located within the fluid conduit 101 between the stopper 141 and the movable plug 120. The movable plug 120 illustrated is spherical, but other shapes are possible (e.g., frustoconical, conical, pyramid, dome, etc.). A seat 130 is also shown, which is shaped to conform to the shape of the movable plug 120. The seat 130 is a separate component from the valve body 110 and is inserted into the valve body 110 at the downstream end. The threaded plug 114 (i.e., the removable upstream portion) including the plug orifice 116 (i.e., the fluid conduit 101) is screwed onto the corresponding thread at the downstream end of the valve body 110. Similarly, as described above, the threaded plug 114 is operable to adjust the spring load of the spring 140 and the spray pressure threshold (i.e., the cracking pressure). Here, during operation of the device 1, the spring 140 is exposed to the fluid.

[0043] Figure 6An embodiment of a spray valve 100 with a valve stem is shown. Here, the spray valve 100 includes a multi-piece movable plug 120, which consists of a cylindrical body 121 and a head 122 attached to the valve stem 124. The valve stem 124 is generally cylindrical and is partially disposed within the anchoring hole 106 of the anchoring portion 105. A stop 141' is located in the upstream portion of the anchoring hole 106. The stop 141' prevents the movable plug 120 from extending beyond a certain distance within the anchoring hole 106. A spring 140 is positioned between the cylindrical body 121 and the anchoring portion 105. During operation of the device 1, the spring 140 is exposed to the fluid. A seal 103" isolates the portion of the valve stem 124 disposed within the anchoring hole 106 from the fluid.

[0044] Figures 7 - 9 Shows Figure 3 A cross-sectional view taken along the Z-Y plane of different embodiments of the pressure relief valve 200 shown in Figure 8 ). Or a valve with a valve stem type valve ( Figure 7 And Figure 9 ). As Figures 4 - 6 Illustrated in, the pressure relief valve 200 includes spray valve threads 208, which engage corresponding pressure relief valve threads 108 of the spray valve 100 when the spray valve 100 is attached to the pressure relief valve 200. The pressure relief valve 200 also includes one or more other mounting locations (not shown), and the aforementioned other mounting locations are optionally operable to receive corresponding fasteners (not shown) to mount the pressure relief valve 200 to the housing 10. Finally, the pressure relief valve 200 includes a pump interface (not shown), which is operable to be operably coupled to the pumping mechanism 30 and receive fluid through the fluid conduit 101.

[0045] As Figures 7 - 9 Illustrated in, the pressure relief valve 200 includes a pressure relief conduit 201, which intersects the fluid conduit 101. As illustrated, the upstream portion of the pressure relief conduit 201 is generally perpendicular to the fluid conduit 101, but it should be understood that other arrangements are possible. The pressure relief conduit 201 leads to both the return line 32 and the vent 202. A seat 230 and a movable plug 220 are disposed along the pressure relief conduit 201 to block the pressure relief conduit until the operator manually opens the pressure relief valve 200 to start the pump or the fluid pressure has exceeded the pressure relief threshold. In the former case, the air contained in the pump 31, the fluid conduit 101, and / or the pressure relief conduit 201 is purged through the vent 202. At the same time, the air is replaced with fluid drawn from the fluid container 50. In the latter case, some pressurized fluid is allowed to flow past the movable plug 220 through the pressure relief conduit 201 to the return line 32 and back to the fluid container 50.

[0046] Figures 7 - 9Each of the pressure relief valves 200 shown therein includes a valve body 210 that includes threads 211 that are operable to engage corresponding threads on the pressure relief valve 200. The valve body 210 is generally cylindrical, but other shapes are possible. The valve body 210 includes one or more seals 203 (e.g., sealing rings, O-rings with corresponding grooves, etc.), and the foregoing seals are operable to prevent any fluid from leaking out of the pressure relief valve 200. Further, each of the pressure relief valves 200 includes a movable plug 220 (e.g., a lift valve, a ball, etc.), a seat 230, and a spring 240. Although Figures 7 - 8 the pressure relief valves 200 shown therein include different internal structures for mounting, securing, and positioning the movable plug 220 and the spring 140, the function of each of the pressure relief valves 200 is generally as follows.

[0047] The spring 240 biases the movable plug 220 toward the seat 230. The movable plug 220 and the seat 230 are positioned in line with the pressure relief conduit 201 such that when the movable plug 220 is located on the seat 230, the pressure relief conduit 201 is blocked and fluid (or air) cannot pass through the plug 220. As discussed above, the pressure relief valve 200 can be opened in one of two ways. Manual compression of the spring 240 via an activation switch can be effected using the activation switch 17, or by fluid pressure if the fluid pressure has reached the pressure relief threshold. Specifically, the pressurized fluid pushes against the head 222, which compresses the spring 240 and retracts the movable plug 220 from the seat 230. The pressure relief threshold is related to the force required to compress or deform the spring 240. It should be understood that the pressure relief threshold can be increased or decreased by adjusting the spring stiffness of the spring 240. For example, replacing the spring 240 with a different spring having a lower or greater spring stiffness (i.e., the force exerted by the spring as calculated by Hooke's law).

[0048] Figure 7 An embodiment of the pressure relief valve 200 is shown that includes a valve stem 224 connected to a cam 251. When the discharge switch 17 is rotated, the cam 251 interferes with a cam plate 250, which in turn pulls the valve stem 224, compresses the spring 240, and retracts the movable plug 240 from the seat 230. The valve stem 224 extends from the movable plug 220 and is integral with the movable plug 220 in some cases. The movable plug 220 also includes a spring flange 242 that is operable to secure the spring 240. The spring 240 is positioned between the spring flange 242 and a stop 241.

[0049] Figure 8Another embodiment of the pressure relief valve 200 is shown, which includes two springs 240a and 240b. As illustrated, spring 240a is positioned entirely around the cylindrical body 221 of the movable plug 220 between the stop 241' and the spring flange 242. The larger spring 240b is positioned partially around the cylindrical body 221 of the movable plug 220 between the spring flange 242 and the stop 241. The present disclosure also contemplates a reversed arrangement. Here, the spring stiffness of spring 240b determines the pressure relief threshold. Conversely, spring 240a has a lower spring stiffness and aids in retracting the movable plug 220 from the seat 230 when manually opening the pressure relief valve. Also shown are course buttress threads 255, which are operable to laterally displace springs 240a and 240b and the movable plug when the drain switch 17 is turned.

[0050] Figure 9 Another embodiment of the pressure relief valve 200 is shown, which includes a valve stem 224 that includes a hook 226 positioned within a hook cavity 227 of the movable plug 220. A spring 240 is positioned around the valve stem 224 between the body 221 of the plug and the stop 241. Also shown are course buttress threads 255, which are operable to laterally displace the valve stem 224 and the movable plug 220 when the drain switch 17 is turned. Specifically, when the drain switch 17 is rotated, the hook 226 abuts against the sidewall of the hook cavity, thereby compressing the spring 240 and retracting the movable plug 220 from the seat 230. The hook cavity 227 is sized to accommodate the lateral movement of the valve stem 224 caused by turning the drain switch 17, thereby engaging the course buttress threads 255.

[0051] The present disclosure has been described in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains to practice the disclosure. It will be understood that the foregoing description of the preferred aspects and modifications of the present disclosure may be made without departing from the spirit or scope of the present disclosure as set forth in the appended claims. The scope of the following claims will be given the broadest interpretation to cover all such modifications and equivalent structures and functions. It is thus intended that the present application not be limited to the particular aspects disclosed, but that the present application will include all aspects falling within the scope of the appended claims.

Claims

1. A stemless valve for a fluid spraying device, comprising: A cylindrical valve body including a sealing end and an open end; a movable plug disposed at least partially within the cylindrical valve body and proximate the open end; an air cavity disposed between the movable plug and the sealing end of the cylindrical valve body; at least one seal surrounding the movable plug, the seal being operable to seal air within the air cavity; a seat shaped to conform to the shape of the movable plug; a spray hole positioned downstream of the seat; a fluid conduit operable to allow fluid from a pump to flow at least partially through the cylindrical valve body to a spray orifice positioned downstream of the seat; as well as A spring is disposed in the air cavity, wherein: The spring is positioned between the sealing end of the cylindrical valve body and the movable plug, When the fluid pressure is below a spray pressure threshold, the spring biases the movable plug against the seat to prevent the fluid from flowing through the fluid conduit to the spray orifice; and When the fluid pressure reaches or exceeds the spray pressure threshold, the spring compresses, thereby at least partially retracting the movable plug from the seat and allowing the fluid to flow through the fluid conduit to the spray orifice.

2. The stemless valve according to claim 1, wherein: The spray pressure threshold is between 800 PSI and 2000 PSI.

3. The stemless valve according to claim 1, wherein: The removable plug further includes a cylindrical body and a head coupled to the cylindrical body.

4. The stemless valve according to claim 3, wherein: The head of the movable stopper has a frustoconical shape.

5. The stemless valve according to claim 4, wherein: The cylindrical body of the removable plug includes at least one groove, and the groove is operable to receive the at least one seal.

6. The stemless type valve according to claim 1, wherein: The spring comprises a compression spring.

7. The stemless valve according to claim 1, wherein: When compressed by the movable plug, the air cavity is operable to act as a damper for the spring to reduce vibrations of the spring caused by operation of the pump or operation of a motor operably connected to the pump.

8. The stemless valve according to claim 1, wherein: The spring is isolated from the fluid.

9. The stemless valve according to claim 1, wherein: The removable stopper further includes a stopper operable to prevent the removable stopper from being retracted beyond a preferred distance from the seat.

10. The stemless type valve according to claim 1, wherein: The sealing end includes a threaded plug that is screwed into the cylindrical valve body.

11. A stemless valve for a fluid spraying device, the stemless valve comprising: A cylindrical valve body including an upstream end and a downstream end; a fluid conduit operable to allow fluid to flow from a pump through the cylindrical valve body to a spray orifice positioned downstream of the cylindrical valve body; a movable plug disposed within the cylindrical valve body; a seat shaped to conform to the shape of the movable plug, the seat being disposed within the cylindrical valve body and adjacent to the upstream end; A spring is disposed in the cylindrical valve body, wherein: When the fluid pressure is below a spray pressure threshold, the spring biases the movable plug against the seat to prevent the fluid from flowing through the fluid conduit to the spray orifice; and When the fluid pressure reaches or exceeds the spray pressure threshold, the spring compresses, thereby at least partially retracting the movable plug from the seat and allowing the fluid to flow through the fluid conduit to the spray orifice.

12. The stemless valve according to claim 11, wherein: The cylindrical valve body further comprises: a downstream portion including the threaded hole; and A removable upstream portion comprising threads disposed about the removable upstream portion, wherein: The threads of the removable upstream portion are operable to engage the threaded bore of the downstream portion to secure the removable upstream portion to the downstream portion, thereby retaining the spring and the movable plug within the cylindrical valve body.

13. The stemless valve according to claim 11, wherein: The spray pressure threshold is between 800 PSI and 2000 PSI.

14. The stemless valve according to claim 11, wherein: The spring comprises a compression spring.

15. A handheld fluid dispensing device, comprising: a housing, the housing comprising a handle; an electric motor positioned within the housing, the electric motor being operable to output rotational motion; a driver positioned within the housing and operably coupled to the electric motor, the driver operable to convert the rotary motion into reciprocating linear motion; an actuator disposed on the housing adjacent the handle, the actuator being operable to actuate the electric motor; a fluid container mounted to the housing, the fluid container being operable to receive and hold a fluid; a pump positioned within the housing and operably coupled to the actuator, the pump operable to draw the fluid from the fluid container, pressurize the fluid, and drive the fluid through the stemless valve to a spray orifice positioned downstream of the stemless valve; The stemless valve comprises: A valve body, the valve body being substantially cylindrical; a fluid conduit operable to allow the fluid to flow from the pump at least partially through the valve body to the spray orifice; a movable plug disposed at least partially within the valve body; a seat shaped to conform to the shape of the movable plug; A spring is disposed in the valve body, wherein: When the fluid pressure is below a spray pressure threshold, the spring biases the movable plug against the seat to prevent the fluid from flowing through the fluid conduit to the spray orifice; and When the fluid pressure reaches or exceeds the spray pressure threshold, the spring compresses, thereby at least partially retracting the movable plug from the seat and allowing the fluid to flow through the fluid conduit to the spray orifice.

16. The handheld fluid dispensing device of claim 15, further comprising: a nozzle guard mounted to the housing; the nozzle guard comprising an aperture; and A reversible nozzle comprising a cartridge, wherein: The cartridge is insertable into the aperture of the nozzle guard and rotatable within the aperture; and The spray hole is arranged in the barrel.

17. The handheld fluid dispensing device of claim 15, wherein: The spray pressure threshold is between 800 PSI and 2000 PSI.

18. The handheld fluid dispensing device of claim 15, wherein: The spring comprises a compression spring.

19. The handheld fluid dispensing device of claim 15, wherein: The valve body further comprises an open end and a sealed end; and The removable plug further comprises a cylindrical body, a head and at least one seal surrounding the cylindrical body; wherein: The cylindrical body of the removable plug encloses an air cavity between the removable plug and the sealing end of the cylindrical valve body; and The at least one seal is operable to seal air within the air cavity.

20. The handheld fluid dispensing device of claim 19, wherein: The head of the movable stopper has a frustoconical shape.

21. A handheld fluid dispensing device, comprising: a housing, the housing comprising a handle; an electric motor positioned within the housing, the electric motor being operable to output rotational motion; a driver positioned within the housing and operably coupled to the electric motor, the driver operable to convert the rotary motion into reciprocating linear motion; an actuator disposed on the housing adjacent the handle, the actuator being operable to actuate the electric motor; a fluid container mounted to the housing, the fluid container being operable to receive and hold a fluid; a pump positioned within the housing and operably coupled to the actuator, the pump being operable to draw the fluid from the fluid container, pressurize the fluid, and drive the fluid downstream of the pump to atomize the fluid; a pressure relief valve connected to and positioned downstream of the pump, the pressure relief valve being operable to activate the pump and redirect the fluid back into the fluid container when a pressure of the fluid output by the pump exceeds a pressure relief threshold; a spray valve connected to and positioned downstream of the pressure relief valve; a nozzle assembly connected to and positioned downstream of the spray valve, the nozzle assembly including a spray orifice operable to atomize the fluid, Wherein, the spray valve comprises: A valve body, the valve body being substantially cylindrical; a fluid conduit operable to allow the fluid to flow from the pressure relief valve at least partially through the valve body to the spray orifice of the nozzle assembly; a frustoconical plug disposed at an end of the valve stem, wherein the frustoconical plug and the valve stem are completely positioned within the valve body; a seat formed to conform to the shape of the truncated cone-shaped plug; a spring disposed around the valve stem and positioned within the valve body, wherein: When the fluid pressure is below a spray pressure threshold, the spring biases the frustoconical plug against the seat to prevent the fluid from flowing through the fluid conduit to the spray orifice; and When the fluid pressure reaches or exceeds the spray pressure threshold, the spring compresses, thereby at least partially retracting the frustoconical plug and the valve stem from the seat and allowing the fluid to flow through the fluid conduit to the spray orifice.

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