Handheld liquid spray gun

Abstract

A handheld spray gun effective for directing a high-pressure, turbulence-free discharge spray. The spray gun comprises a barrel with an angled handle, a barrel liquid supply conduit for directing liquid from a liquid supply section to the discharge orifice of the barrel, and a valve stem disposed within the barrel liquid supply conduit and moving relative to the discharge orifice between an open position and a closed position. A magnet assembly comprising a pair of magnets disposed outside the liquid supply conduit is effective in biasing the valve stem to the closed position of the discharge orifice in accordance with the repulsive magnetic force of the magnets, and a trigger is actuated to move the valve stem against the repulsive magnetic force of the magnet assembly to open the discharge orifice, and when the trigger is released, the opposing magnetic force of the magnets pushes the valve stem back to the closed position of the discharge orifice.

Description

BACKGROUND ART

[0001] Cross-Reference to Related Applications

[0002]

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 538,206 filed on September 13, 2023, the content of which is incorporated herein by reference. Field of the Invention

[0003]

[0002] The present invention relates generally to handheld liquid spray guns, and more specifically to a handheld spray gun adapted to direct a high-pressure cleaning fluid. Background of the Invention

[0004]

[0003] Many industrial production applications rely on extensive cleaning both during production operation and during dedicated cleaning periods to ensure that the production area is a clean and safe environment for both workers and products. This is particularly important in cases such as food production, for example. Production lines must be thoroughly cleaned and sterilized between production runs to ensure that food products are free of contamination resulting from previous production processes.

[0005] Regardless of the industry, one of the most common and conveniently used methods for cleaning such production areas is a general-purpose handheld cleaning gun. These handheld devices are easy to hold and maneuver, and a trigger mechanism opens a valve to release high-pressure water or cleaning solution, which is sprayed onto surfaces contaminated with products, excess components, and general dirt. Conventional such guns have primarily relied on an internal spring-loaded mechanism that controls the opening and closing of the valve that regulates fluid distribution. Internal control springs are generally disposed around the fluid control valve in the liquid flow path, which can cause turbulence in the dispensed liquid and impair the cleaning effect of the discharged spray. Turbulence caused by the directivity of high-pressure fluid through the gun can further compromise stable and reliable trigger control of the gun.

[0006] Objects and Summary of the Invention

[0007]

[0004] The object of the present invention is to provide a handheld spray gun equipped with a valve biasing component that facilitates the turbulent transmission of the liquid flow through the spray gun when a high-pressure liquid is sprayed.

[0008]

[0005] Another objective is to provide a handheld spray gun having the above-mentioned features and without using valve biasing springs or the like in the liquid flow path that can obstruct or create turbulence in the high-pressure liquid dispensed from the spray gun.

[0009]

[0006] Another objective is to provide the handheld spray gun of the type described above, which has a non-mechanical valve biasing configuration that provides a distinctive trigger pull feel and facilitates the operation of the gun when spraying high-pressure liquid.

[0010]

[0007] Other objects and advantages of the present invention will become apparent by reading the following detailed description and referring to the drawings. These specific objects are not intended to limit the present invention. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a partially cutaway perspective view of a handheld spray gun according to the present invention, showing the state in which the trigger is released and the valve is closed. [Figure 2] Figure 2 is a partially cutaway perspective view similar to Figure 1, but shows the valve in the open position with the trigger activated. [Figure 3] Figure 3 is an enlarged longitudinal section view of an example spray gun, showing the state where the trigger is released and the valve is in the closed position. [Figure 4] Figure 4 is an enlarged longitudinal cross-sectional view of a spray gun, similar to an example in Figure 3, showing the valve in the open position with the trigger activated. [Figure 5] Figure 5 is an enlarged partial longitudinal cross-sectional view of the barrel liquid supply conduit of an example spray gun, taken along the plane of line 5-5 in Figure 4. [Figure 6] Figure 6 is a horizontal cross-sectional view taken along the plane of line 6-6 in Figure 3. [Figure 7] Figure 7 is a horizontal cross-sectional view taken along the plane of line 7-7 in Figure 4. [Figure 8] Figure 8 is an enlarged horizontal cross-sectional view of a magnetic valve biasing assembly of an example embodiment, showing the state in which the magnet is separated from the valve in the closed position. [Figure 9] Figure 9 is an enlarged horizontal cross-sectional view similar to Figure 8, showing the state where the magnet is closer and the valve is in the open position.

[0012]

[0017] While various modifications and alternative configurations are possible with respect to the present invention, the drawings show exemplary embodiments, which are described in detail below. However, the present invention is not intended to be limited to the specific forms disclosed, but rather to encompass all modifications, alternative configurations, and equivalents that fall within the spirit and scope of the invention.

[0013] Detailed description of the invention

[0014]

[0018] Referring more closely to the drawings, a spray gun 10 according to the present invention is shown. The spray gun 10 has an outer casing or housing 11 including a horizontally positioned barrel 12 and a handle 14 supported below the barrel 12, with an operating trigger 15 mounted on the underside of the barrel 12 in front of the handle 14. In this case, the spray gun 10 has a trigger guard 16 which extends outward from the underside of the barrel 12, surrounds the trigger 15, and is coupled to the lower end of the handle 14.

[0015]

[0019] The spray gun 10 has a liquid inlet conduit 18 disposed within the handle 14, the lower end of which is connected to a liquid supply unit (a supply unit for cleaning fluid or other liquid pressurized to a maximum of approximately 350 psi-1000 psi). The liquid inlet conduit 18 communicates with a barrel liquid supply conduit 20 housed within the barrel 12 and oriented transversely, in this case horizontally, the conduit 20 communicates with an orifice member 21, in which case the orifice member 21 defines a central discharge orifice 22, the central discharge orifice 22 has an outwardly flared end 24. The orifice member 21 has an upstream end 25 with an external thread on the upstream side, which is secured within the downstream end of the barrel liquid supply conduit 20, and furthermore, a sealing member 26 such as a known type of O-ring is fitted to the upstream end of the discharge orifice 22 to form a valve seat.

[0016]

[0020] An elongated valve stem 30, having a valve pintle 31 at its downstream end, is centrally positioned within the barrel liquid supply conduit 20 and moves relative to the valve between an open position and a closed position, as described later. A flow straightener 32 attached to the valve stem 30 keeps the valve stem 30 central within the barrel liquid supply conduit 20 and ensures a uniform flow through the discharge orifice 22. In this case, the liquid flow straightener 32 is positioned between the rear of the pintle 31 and the stepped portion 34 on the valve stem 30 (Figures 6 and 7) and moves together with the valve stem 30. The fins 35 of the flow straightener 32 (Figure 5) define a plurality of liquid flow passages 36 arranged at circumferential intervals and contact the inner diameter of the barrel liquid supply conduit 20, keeping the valve stem 30 and valve pintle 31 central within the barrel liquid supply conduit 20.

[0017]

[0021] To realize the key features of this embodiment, the spray gun 10 has a non-mechanical valve biasing component positioned outside the liquid flow path so as not to obstruct or create turbulence in the liquid passing through the spray gun, thereby facilitating trigger control during gun operation when dispensing high-pressure liquid. More specifically, a magnet assembly is mounted on the outside of the upstream end of the barrel liquid supply conduit 20, and the assembly includes a pair of magnets 40A and 40B, with their like poles facing each other to generate a counter-magnetic force between them. In this case, the magnets 40A and 40B are housed in a cylindrical housing 41 (Figures 8 and 9) mounted adjacent to the upstream end of the barrel liquid supply conduit 20. The magnet housing 41 has a cylindrical hub 42 with external threads on the downstream side, which is secured within the upstream end of the barrel liquid supply conduit 20. The outer, or upstream, end of the magnet housing 41 is closed by a removable end cap ring 42, such as a known C-shaped retaining ring, and the rear extension 30a of the valve stem 30 extends outward through the center of the magnet housing 41 and through the central opening of the end cap ring 42.

[0018]

[0022] In this case, magnets 40A and 40B are ring magnets attached to the rear extension of the valve stem 30, with magnet 40A mounted at the front and magnet 40B mounted at the rear. The rear magnet 40B is held against the end cap ring 42 of the housing by the opposing magnetic force of magnets 40A and 40B.

[0019]

[0023] In this case, the front magnet 40A is pressed against the stepped portion 44 (Figures 6 and 7) of the valve stem 30 at the front end of the magnet housing 41 by the magnetic opposing force between magnets 40A and 40B. As a result of being pressed against the stepped portion 44, the magnetic opposing force between magnets 40A and 40B causes the front magnet 40A to move forward, and consequently the valve stem 30, the rectifier 32, and the valve pintle 31 also move forward, causing the valve pintle 31 to close the valve's release orifice 21.

[0020]

[0024] A trigger actuation linkage is provided to resist the magnetic force that advances the valve stem 30 to close the discharge orifice 21, which includes a U-shaped linkage 45 that converts the angular motion of the trigger 15 into horizontal movement of the U-shaped linkage 45 to retract the valve stem 30 to the valve open position. The U-shaped linkage 45 in this case includes a pair of leg portions 45a extending along both sides of the barrel liquid supply conduit 20, and a transverse connecting end portion 45b through which the end of the valve stem 30 passes. A large-diameter head 30b is disposed at the distal end of the valve stem 30, and is arranged in a counterbore opening outward on the connecting end portion 45b of the linkage. The upstream end of the leg portion 45a of the linkage is disposed in the eccentric slot 46 of the trigger 18 (FIGS. 1 and 2), whereby when the trigger 18 pivots from the valve closed position shown in FIGS. 1, 3 and 6 to the valve open position shown in FIGS. 2, 4 and 7, the linkage 45 moves rearward to pull the valve stem 30 rearward, opening the discharge orifice 21 of the valve and simultaneously bringing the front magnet 40A close to the rear magnet 40B.

[0021]

[0025] When the linkage 45 and the valve stem 30 are pulled rearward, the discharge orifice 21 is opened, and liquid passes through the barrel liquid supply conduit 20 and is discharged from the spray gun. During this period, the front magnet 40A is moved rearward inside the magnet housing 41 by the step portion 44 of the valve stem 30. It is pulled to approach the rearmost magnet 40B, which is held in the magnet housing 41 by the end cap ring 42. As the distance between the magnets 40A and 40B decreases, the magnetic opposing force therebetween increases until it reaches a maximum level when the valve pintle 31 is fully retracted from the valve discharge orifice 24. At this point, the trigger 15 applies a linear force equivalent to the magnetic opposing force generated by the magnets 40A and 40B to hold the valve stem 30 in that position.

[0022]

[0026] When the trigger 15 is released, a linear force equal to the magnetic opposing force generated by magnets 40A and 40B is removed. At this time, the increased magnetic opposing force between magnets 40A and 40B causes them to experience a force moving away from each other. The rearmost magnet 40B is held in place by the rear plate and cannot move any further rearward. Therefore, the front magnet 40A is forced to move forward inside the magnet housing 7. As the magnetic opposing force moves the front magnet 40A forward, the valve stem 30 is also pushed forward because magnet 40A is engaged against the stepped portion 44 of the valve stem 30. When magnet 40A pushes the valve stem 30 forward, the rectifier 32 and valve pintle 31 connected to the valve stem 30 are also pushed forward. The forward magnet 40A, valve stem 30, rectifier 32, and pintle 31 are pushed forward by the magnetic opposing force between magnets 40A and 40B until the valve pintle 31 engages with the seal 26 and closes the release orifice 21. When magnets 40A and 40B are at their maximum separation, the magnetic opposing force between them is minimal, but still sufficient to hold the valve pintle in the closed position.

[0023]

[0027] From the above, it can be seen that a handheld spray gun equipped with a valve biasing mechanism that facilitates turbulent transmission of high-pressure liquid through the spray gun is provided. A magnetic biasing mechanism further facilitates trigger control when spraying such high-pressure fluid.

Claims

1. A spray gun, wherein the spray gun is A housing including a barrel and a handle positioned at an angle to the barrel, An orifice member defining a discharge orifice adjacent to the downstream end of the barrel, wherein the barrel has a barrel liquid supply conduit for guiding liquid from a liquid supply to the discharge orifice, A valve stem is disposed within the barrel liquid supply conduit so as to be relatively movable between the open position and the closed position of the discharge orifice, A magnet assembly for biasing the valve stem to the closed position of the release orifice in accordance with the repulsive magnetic force of the magnet assembly, A trigger is activated to move the valve stem against the repulsive magnetic force of the magnet assembly, thereby enabling the flow of liquid through the liquid supply conduit and releasing it from the discharge orifice. Equipped with, A spray gun wherein, when the trigger is released, the repulsive magnetic force of the magnet assembly biases the valve stem to the closed position of the discharge orifice.

2. The spray gun according to claim 1, further comprising a trigger actuation unit for converting the angular motion of the trigger into translational motion of the valve stem and for retracting the valve stem against the magnetic force of the magnet assembly.

3. The spray gun according to claim 1, wherein the magnet assembly includes a pair of magnets, and the like poles of the magnets are arranged facing each other to generate a counter-magnetic force between the magnets.

4. The spray gun according to claim 1, wherein the magnet assembly is disposed on the outside of the liquid supply conduit.

5. The spray gun according to claim 4, wherein the magnet assembly is mounted on the outside of the upstream end of the barrel liquid supply conduit.

6. The spray gun according to claim 1, wherein the handle includes a liquid inlet conduit that connects the inlet of the barrel liquid supply conduit to the liquid supply unit.

7. The spray gun according to claim 3, wherein the pair of magnets are ring magnets mounted on the rear extension of the valve stem, one of the ring magnets is mounted rearward relative to the stop surface fixed to the barrel liquid supply conduit, and the other of the magnets is mounted forward relative to the stop surface on the valve stem, and the repulsive magnetic force of the magnets causes the front-mounted magnet to be pressed against the stop surface on the valve stem, and the rear-mounted magnet to be pressed against the stop surface fixed to the liquid supply conduit.

8. The spray gun according to claim 7, wherein the magnet is disposed within a cylindrical housing attached to the upstream end of the barrel liquid supply conduit, and the stopping surface of the rearward-mounted magnet is the upstream end cap of the housing.

9. The spray gun according to claim 6, wherein the barrel includes an outer barrel housing through which the barrel liquid supply conduit extends, and the handle includes an outer housing through which the liquid inlet conduit of the handle extends.

10. The spray gun according to claim 1, comprising a flow straightening device in the barrel liquid supply conduit, the valve stem being held centrally within the barrel liquid supply conduit, and maintaining a uniform flow of liquid through the liquid supply conduit.

11. The spray gun according to claim 10, wherein the rectifier has a plurality of radial fins, and the plurality of radial fins define a plurality of liquid flow paths that are spaced apart in the circumferential direction.

12. A spray gun, wherein the spray gun is A housing comprising a barrel and a handle positioned at an angle to the barrel, An orifice member that defines a discharge orifice adjacent to the downstream end of the barrel, The barrel has a barrel liquid supply conduit for guiding liquid from the liquid supply section to the discharge orifice, and the orifice member A valve stem is disposed within the barrel liquid supply conduit so as to be relatively movable between the open position and the closed position of the discharge orifice, A magnet assembly is attached to the upstream end of the barrel liquid supply conduit and includes a pair of magnets arranged with their like poles facing each other, which generates a repulsive magnetic force between the magnets to bias the valve stem to the closed position of the discharge orifice, A trigger rotatably mounted on the housing, An operating linkage that converts the pivoting motion of the trigger into the translational motion of the valve stem, causing the valve stem to retract against the repulsive magnetic force of the magnet, thereby opening the discharge orifice and enabling the flow of liquid through the liquid supply conduit to discharge from the discharge orifice, Equipped with, A spray gun wherein, when the trigger is released, the repulsive magnetic force of the magnet biases the valve stem to the closed position of the discharge orifice.

13. The spray gun according to claim 12, wherein the handle includes a liquid inlet conduit that connects the inlet of the barrel liquid supply conduit to the liquid supply unit.

14. The spray gun according to claim 12, wherein the pair of magnets are ring magnets mounted on the rear extension of the valve stem, one of the ring magnets is mounted rearward relative to the stop surface fixed to the barrel liquid supply conduit, and the other of the magnets is mounted forward relative to the stop surface on the valve stem, and the repulsive magnetic force of the magnets causes the front-mounted magnet to be pressed against the stop surface on the valve stem, and the rear-mounted magnet to be pressed against the stop surface fixed to the liquid supply conduit.

15. The spray gun according to claim 14, wherein the magnet is disposed within a cylindrical housing attached to the upstream end of the barrel liquid supply conduit, and the stopping surface of the rearward-mounted magnet is the upstream end cap of the housing.

16. The spray gun according to claim 12, wherein the barrel includes an outer barrel housing through which the liquid supply conduit extends, and the handle includes an outer housing through which the liquid inlet conduit of the handle extends.

17. The spray gun according to claim 12, comprising a flow straightening device having a plurality of radial vanes mounted in the barrel liquid supply conduit, the valve stem being held centrally in the barrel liquid supply passage to maintain a uniform flow of liquid through the liquid supply conduit.

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