Spray tip holder for airless spray gun

Abstract

Spray tip holder, for airless spray gun, having a body, a nut, a tip interface mounted with the body and having a first cylindrical section designed to be fitted to the spray gun and a second cylindrical section, perpendicular to the first cylindrical section and designed for receiving a spray tip, characterized in that, the second cylindrical section of the tip interface comprises a first entry for a spray tip and a second entry, located opposite the first entry and designed to receive a spray tip, and that the body comprises a first shoulder located at the first entry and defining a first distance between the first shoulder and the axis of the first cylindrical section and a second shoulder, located at the second entry and defining a second distance between the second shoulder and the axis of the first cylindrical section.

Description

[0001] Spray tip holder for airless spray gun

[0002] Introduction

[0003] The present invention relates generally to fluid spraying systems. More particularly, the invention relates to a spray tip holder to be mounted on a spray gun and designed to receive the spray tip. Fluid spraying systems are commonly used in a wide variety of applications, from industrial assembly of all kinds to home painting. Handheld sprayers can be used by a human operator, while automated sprayers are typically used in mechanized manufacturing processes. Interchangeable spray tips are commonly used in the painting field to accommodate the type of paint, the coating finish and the spray pattern desired.

[0004] Background Art

[0005] An airless sprayer pumps up and pressurizes the paint without the use of air. The paint is then fed through a small hole (referred to as an orifice) within the spray tip under high pressure which can be up to 530 bars / 7700 psi. This process atomizes the paint in a controlled fan width and flow rate. Spray tip size and airless pump pressure determine the paint material flow rate. The spray tip, in particular the nozzle assembly, also creates the fan pattern, spraying angle and spraying volume.

[0006] The spray tip should be replaced often during the painting operation to obtain the right finish, surface coverage and coating thickness for the specific application. The use of the spray tip entails wear, and the shape of the spray tends to change over time. This is why the spray guns, in particular the spray tip holders, are designed to receive interchangeable spray tips. The spray tip comprises a nozzle carrier comprising a nozzle assembly which defines the shape of the spray when fluid passes through it. When the nozzle carrier is rotated into the spray position, pressurized fluid (typically paint) is forced forward through the nozzle assembly and exits at high velocity along the central longitudinal axis of the nozzle assembly.

[0007] The spray tip holder comprises a body, generally realized in hard plastic ( polyamide PA66, ABS, etc) and having perforated two winds, a tip interface for receiving the interchangeable tip and a nut, for fixing the spray tip holder to the spray gun. The tip interface comprises a cylindrical portion having a through passage, for which one side is in contact with the spray gun and the other side being in the form of a hollow cylinder having the interior diameter substantially equal to the outer diameter of the spray tip, so that the second section of the tip interface can fit snugly around the spray tip. The body comprises a shoulder for indexing the penetration of the spray tip into the hollow cylinder so that the nozzle of the spray tip is centered with the through passage of the tip interface.

[0008] Brief description of the invention

[0009] One of the problems is the proposition on the market of various different types of spray tip. A spray tip is defined by its diameter, the type of nozzle and the distance between the axis of the spray nozzle and a tab, the role of the tab being to define the proper insertion into the spray tip holder so that the spray nozzle is centered with the axis of the tip interface. The distance between the tab and the axis of the nozzle can vary depending on the manufacturers. In the same manner, the diameter can also vary. It is a way to limit, by the manufacturers of spray guns, the possibility for the customers to buy compatible spray tips. It is to be noted that the spray tips are the part often changed and therefore the market of spray tips is very competitive with a large selection of spray tips available from different makers

[0010] A first solution was proposed to address the problem of the different distances between the tab and the nozzle's axis by providing different spacers. The tip itself is manufactured according to the longer distance and if the spray tip holder is designed for a smaller distance, spacer (or spacers) in the form of a ring or washer, are slid into the nozzle carrier to adapt the length to the right length. It is easy to imagine the difficulty, in an industrial environment or a construction site, to determine which type of spray tip holder the user is currently using, and to determine the right spacer to use and to slide around the nozzle carrier.

[0011] The below invention proposes a spray tip holder, for a spray gun, having a body, a nut, a tip interface mounted with the body and having a first cylindrical section designed to be fitted to the spray gun and a second cylindrical section, perpendicular to the first cylindrical section and designed for receiving the spray tip, characterized in that, the second cylindrical section comprises a first entry for a spray tip and a second entry, located opposite the first entry and designed to receive a spray tip, and that the body comprises a first shoulder located at the first entry and defining a first distance between the first shoulder and the axis of the first cylindrical section and a second shoulder, located at the second entry and defining a second distance between the second shoulder and the axis of the first cylindrical section.

[0012] With this design, the spray tip holder can receive two different spray tips having different characteristics such as a different distance between the nozzle axis and the tab.

[0013] Brief description of the figures

[0014] The present invention will be better understood with the help of the attached figures, namely :

[0015] Figure 1 illustrates the spray tip holder with a view on the first section of the tip interface,

[0016] Figure 2 illustrates two different spray tips with different distance between the axis of the nozzle and the tab,

[0017] Figure 3 illustrates a perspective view of the spray tip holder, Figure 4 illustrates the front view of two different spray tips, Figure 5 illustrates the side view of two different spray tips.

[0018] Detailed description

[0019] A spray tip holder is made of mainly three parts (see figure 1). The body (la, lb) which is realized generally in PA66 / ABS and comprises two wings (la) for preventing injuries for the user while spraying and a section (lb) for receiving the tip interface. The tip interface, typically made of stainless steel or brass, is assembled with the body and form one element. The tip interface comprises two sections, the first section being adapted to be mounted on the spray gun and has a first cylindrical section terminated by a flat surface (applied on the spray gun) and the second section which is a second cylindrical section orthogonal to the first section. The first cylindrical section is hollow and allows the paint to be pushed by the spray gun through the tip interface to terminate on the spray tip. The second cylindrical section is visible on the figure 1, item 3, and creates a cylindrical passage for the spray tip. The second section has an opening located at the axis of the first section, allowing the high- pressured paint to transit to the spray tip. The body serves to index properly the spray tip into the second cylindrical section. A shoulder (4) is formed in the body to stop the insertion of the spray tip when the nozzle of the spray tip is aligned with the axis of the first cylindrical section of the tip interface.

[0020] The last part of the spray tip holder is a nut (5) used to secure the spray tip holder to the spray gun. It is to be noted that the nut may have a fluted, knurled or hexagonal exterior to secure the spray tip holder to the gun with a spanner. In addition there is a plastic sleeve (PA66) that can be slidden around the nut in order for the user to tighten the nut to the spray gun by hand.

[0021] The main characteristic of the spray tip holder of the present invention is in the body. In the known solutions, the body has one opening to allow the spray tip to enter into the tip interface and the opposite side is closed.

[0022] The figure 2 illustrates the present invention with the body having two openings, located opposite to each other. This allows the introduction of a spray tip on either side of the body.

[0023] The main interest to have two openings is to be able to accommodate two different spray tips, having different physical dimensions (.e.g. different nozzle carrier lengths and diameters) On the figure 2, the left spray tip (A) has a first distance DI between the tab (4a) and the nozzle axis (5a). The body of the spray tip holder comprises a first shoulder (see figure 1, item 4) shaped so that the distance of the flat surface of the shoulder and the axis (6) of the first cylindrical section of the tip interface is equal to the distance DI.

[0024] In the same manner, the right spray tip (B) has a second distance D2 between the tab (4b) and the nozzle axis (5b). The body of the spray tip holder comprises a second shoulder to the opposite side of the first shoulder of the body, shaped so that the distance of the flat surface of the second shoulder and the axis (6) of the first cylindrical section of the tip interface is equal to the distance D2. It is apparent that the distance DI is different than the distance D2.

[0025] The body of the spray tip holder of the present invention is therefore not symmetrical, the distance between the first shoulder (4), located on one side of the body, and the axis (6) of the tip interface, is different than the distance between the second shoulder, located to the opposite side of the body, and the axis (6) of the tip interface.

[0026] The figure 3 is a perspective view of the spray tip holder. The first opening (3) is visible on one side of the body, and we can also see the second opening (7) on the other side of the body. On the figures 1 and 3, only one shoulder (4) is visible but a similar shoulder is formed on the body around the second opening (7, figure 3). The shoulder defines the penetration of the spray tip into the body.

[0027] The figure 4 and 5 illustrates two different spray tips, side by side. The distance between the tab (4a, 4b) of the spray tips and the axis of the nozzle (5a, 5b) is different. The nozzle (6a, 6b) of each spray tip is therefore located at different distance, initially meant for different spray tip holders. With the body as proposed by the present invention, these spray tips can be used in the same spray tip holder.

[0028] As mentioned previously, the shoulder has the role of indexing the spray tip during the introduction of the spray tip into the spray tip holder. The spray tip comprises a tab (4a, 4b) to stop the introduction of the nozzle carrier into the first cylindrical section of the tip interface. While the tab is pushed until stopped by the shoulder, the axis of the nozzle is aligned with the axis of the first cylindrical section and the spray gun is ready for its operation.

[0029] Various executions of the shoulder can be proposed, in order to assist the operator in his daily work. In a first embodiment, the shoulder has a circular shape adapted to receive a tab in the form of a ring. The spray tip when in position, can freely rotate and stay in contact with the shoulder of the body.

[0030] In another embodiment, the shoulder (4) comprises a groove section (2) cooperating with a corresponding tab of the spray tip.

[0031] In the examples of the figure 2 and 3, the spray tip comprises a tab (4a, 4b) which is a quarter of a ring. The groove (2) has a larger section only in a small section thus allowing the tab to enter fully into the body and being in contact with the shoulder. The rotation of the spray tip is guided by the groove allowing a rotation of 90 degrees on either side. The groove therefore allows the rotation to 180 degrees of the tab.

[0032] One side of the rotation corresponds to the spray position and the other side of the rotation corresponds to the cleaning position of the spay tip. It is to be noted that once the spray tip is rotated to either side, the spray tip cannot be removed since the tab is engaged in the groove. The shape of the groove helps the user to place the spray tip perfectly aligned with the axis of the tip interface.

[0033] In many cases, the spray tips have different diameters. Since the second section of the tip interface of the spray tip holder of the present invention has a larger diameter compared to existing tip interfaces, then a large selection of different spray tips, with different diameters can be inserted on either side of the spray tip holder.

Claims

Claims1. Spray tip holder, for airless spray gun, having a body (la, lb), a nut (5), a tip interface mounted with the body (lb) and having a first cylindrical section designed to be fitted to the spray gun and a second cylindrical section, perpendicular to the first cylindrical section and designed for receiving a spray tip, characterized in that, the second cylindrical section of the tip interface comprises a first entry for a spray tip and a second entry, located opposite the first entry and designed to receive a spray tip, and that the body comprises a first shoulder located at the first entry and defining a first distance between the first shoulder and the axis of the first cylindrical section and a second shoulder, located at the second entry and defining a second distance between the second shoulder and the axis of the first cylindrical section.

2. The spray tip holder of the claim 1, wherein the first distance is different than the second distance.

3. The spray tip holder of the claim 1 or 2, wherein at least one shoulder comprises a groove to cooperate with a tab of the spray tip and limit the rotation to 180 degrees of the tab.

4. The spray tip holder of any of the claims 1 to 3, wherein the diameter of the second cylindrical section is designed to receive the larger diameter of spray tips.

5. The spray tip holder of any of the claims 1 to 4, wherein the nut comprises a plastic sleeve that can be slidden around the nut in order for the user to tighten the nut to the spray gun by hand.

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