Spray tube assembly of a rotary spray gun

Abstract

 A spray tube assembly (1) includes a first bearing (14), a reinforcing tube (13), a second bearing (15) and a gasket ring (16) respectively sleeved onto a nozzle tube and then inserted with the nozzle tube into a spray tube to constitute a modularized structure of spray tube assembly for quick connection to the barrel of a spray gun in a detachable manner. The modularized structure of spray tube (11) assembly facilitates installation and maintenance.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention:

[0001] The present invention relates to a rotary spray gun for cleaning purposes and more particularly, to a spray tube assembly of a rotary spray gun, which is formed by sleeving a first bearing, a reinforcing tube, a second bearing and a gasket ring onto a nozzle tube and then inserting with the nozzle tube into a spray tube to constitute a modularized structure that facilitates installation and maintenance.

2. Description of the Related Art:

[0002] Water spray gun or pistol nozzle is an implement controllable by a control lever to output a forced flow of water. When performing a cleaning work, brushes, wipes, cleaning cloth, and/or many other cleaning tools may be used with a water spray gun or pistol nozzle. Further, after washing with water, a piece of cloth is usually used to dry and clean the washed object. This cleaning method takes much time and labor and consumes a big amount of water. To avoid these problems, rotary spray guns are created.

[0003] FIG. 8 illustrates a known design of rotary spray gun. According to this design, the rotary spray gun A comprises a front barrel A1, a spray tube A12 connected to the front connection end A11 of the front barrel A1, a water tube A13 connected to an external water container and suspending in the front barrel A1, and a nozzle assembly B mounted inside the spray tube A12. The nozzle assembly B comprises a delivery tube B1 connected to the front connection end A11 of the front barrel A1 for input of water from the water tube A13 and a flow of compressed air being guided from an external compressed air source into the front barrel A1, a cylindrical tube B2 mounted in the spray tube A12 around the delivery tube B1, a curved nozzle tip B4, a connector B3 that connects the curved nozzle tip B4 to the delivery tube B1, and bearings B5 mounted in the cylindrical tube B2 to support the delivery tube B1 and the connector B3, allowing rotation of the curved nozzle tip B4 with the cylindrical tube B2 relative to the delivery tube B1. When a flow of water and compressed air mixture is being forced through the curved nozzle tip B4, the curved nozzle tip B4 is forced to rotate with the cylindrical tube B2 relative to the delivery tube B1.

[0004] The aforesaid rotary spray gun is functional, however it still has drawbacks as follows:

1. The assembly process of the rotary spray gun is complicated. During installation, the delivery tube B1, the cylindrical tube B2, the connector B3 and the curved nozzle tip B4 must be assembled at first so that the nozzle assembly B can be mounted inside the spray tube A12 to have the delivery tube B1 be connected to the front connection end A11 of the front barrel A1. After installation of the nozzle assembly B, the spray tube A12 can then be fastened to the front barrel A1. This installation procedure wastes much time and labor.

2. When a flow of water and compressed air mixture is being forced through the curved nozzle tip B4, the curved nozzle tip B4 is forced to rotate with the cylindrical tube B2 relative to the delivery tube B1 at a high speed. During rotation of the curved nozzle tip B4 with the cylindrical tube B2, the delivery tube B1 is caused to vibrate. After a long use of the rotary spray gun, the weight of the cylindrical tube B2, the connector B3 and the curved nozzle tip B4 may cause the delivery tube B1 to break during rotation of the curved nozzle tip B4, resulting in an accident.

[0005] Therefore, it is desirable to provide a measure that eliminates the drawbacks of the aforesaid rotary spray gun.

SUMMARY OF THE INVENTION

[0006] The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a spray tube assembly for rotary spray gun, which has a modularized structural design, facilitating installation and maintenance.

[0007] To achieve this and other objects of the present invention, a spray tube assembly comprises a spray tube, a nozzle tube, a first bearing, a reinforcing tube, a second bearing and a gasket ring. The first bearing, the reinforcing tube, the second bearing and the gasket ring are respectively sleeved onto the nozzle tube in proper order and then inserted with the nozzle tube into the spray tube, thereby constituting a modularized structure of spray tube assembly for quick connection to the barrel of a spray gun in a detachable manner. The modularized structure of spray tube assembly facilitates installation and maintenance.

[0008] Further, the gasket ring is abutted against the outer side of the first bearing and kept in friction engagement with the inside wall of the connection portion of the spray tube tightly, securing the second bearing to an annular step in the connection portion of the spray tube firmly and avoiding water leakage..

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] 

FIG. 1 is an elevational assembly view of a spray tube assembly and a barrel for rotary spray gun in accordance with a first embodiment of the present invention.

FIG. 2 is an exploded view of the assembly shown in FIG. 1.

FIG. 3 is a sectional elevation of the spray tube assembly in accordance with the first embodiment of the present invention.

FIG. 4 is a schematic sectional view showing the spray tube assembly installed in a rotary spray gun according to the first embodiment of the present invention.

FIG. 5 corresponds to FIG. 4, showing the nozzle tube rotated in the spray tube during operation of the rotary spray gun.

FIG. 6 is a schematic sectional view, showing another application example of the spray tube assembly according to the first embodiment of the present invention.

FIG. 7 is an exploded view of a spray tube assembly in accordance with a second embodiment of the present invention.

FIG. 8 is a schematic sectional side view of a conventional rotary spray gun.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0010] Referring to FIGS. 1 and 2, a spray tube assembly 1 for rotary spray gun in accordance with a first embodiment of the present invention is shown comprising a spray tube 11, a nozzle tube 12, a reinforcing tube 13, a first bearing 14, a second bearing 15 and a gasket ring 16.

[0011] The spray tube 11 is a hollow cylindrical member having one end thereof terminating in an orifice 111 and the other end thereof terminating in a connection portion 112 that defines a circular mounting hole 1121 and an annular step 1122 at the inner end of the circular mounting hole 1121.

[0012] The nozzle tube 12 has an elongated tubular body portion 121 mounted in the spray tube 11 and a nozzle tip 122 obliquely extended from one end of the elongated tubular body portion 121 at an angle and suspending inside the spray tube 11 in proximity to the orifice 111.

[0013] The reinforcing tube 13 is mounted inside the spray tube 11 around the elongated tubular body portion 121 of the nozzle tube 12.

[0014] The first bearing 14 is attached to one end of the reinforcing tube 13 around one end of the elongated tubular body portion 121 of the nozzle tube 12 near the nozzle tip 122 and kept in contact with the inside wall of the spray tube 11.

[0015] The second bearing 15 is attached to the other end of the reinforcing tube 13 around the other end of the elongated tubular body portion 121 of the nozzle tube 12 near the connection portion 112 and kept in contact with the inside wall of the spray tube 11.

[0016] The gasket ring 16 is attached to one side of the second bearing 15 opposite to the reinforcing tube 13 and kept in contact with the inside wall of the spray tube 11 near the connection portion 112.

[0017] Further, a fitting 113 is fixedly mounted in the circular mounting hole 1121 of the connection portion 112 of the spray tube 11. The fitting 113 is a metal ring having an inner thread 1131.

[0018] Referring to FIGS. 3 and 4 and FIGS. 1 and 2 again, during installation of the spray tube assembly 1, sleeve the first bearing 14, the reinforcing tube 13, the second bearing 15 and the gasket ring 16 onto the elongated tubular body portion 121 of the nozzle tube 12 in proper order, and then aim the nozzle tip 122 of the nozzle tube 12 at the connection portion 112 of the spray tube 11 axially and insert the nozzle tube 12 into the spray tube 11 to force the first bearing 14, the second bearing 15 and the gasket ring 16 into friction engagement with the inside wall of the spray tube 11. At this time, the second bearing 15 which has an outer diameter relatively greater than the first bearing 14 is abutted against the annular step 1122 in the circular mounting hole 1121 of the connection portion 112 of the spray tube 11, and the gasket ring 16 is abutted against the outer side of the first bearing 14 and kept in friction engagement with the inside wall of the connection portion 112 of the spray tube 11 tightly. The gasket ring 16 can be a compressible ring made of cotton knit fabric or a ring cushion made of an elastic plastic material. Thus, the gasket ring 16 firmly secures the second bearing 15 to the annular step 1122 in the circular mounting hole 1121 of the connection portion 112 of the spray tube 11. Thereafter, the fitting 113 is fixedly mounted in the circular mounting hole 1121 of the connection portion 112 of the spray tube 11. Thus, the pray tube 11, the nozzle tube 12, the reinforcing tube 13, the first bearing 14, the second bearing 15, the gasket ring 16 and the fitting 113 are assembled, forming the desired spray tube assembly 1.

[0019] Referring to FIGS. 3 and 4 again, after the spray tube assembly 1 has been assembled, the spray tube assembly 1 is then fastened to the barrel 21 of a spray gun 2 by means of threading the inner thread 1131 of the fitting 113 onto an outer thread 2111 around the periphery of the front connection portion 211 of the barrel 21 of the spray gun 2.

[0020] Referring to FIG. 5, when the user pressed the control lever 23 of the spray gun 2, a flow of compressed air or fluid is forced into the barrel 21 through an intake port 22. The intake flow of compressed air or fluid is then guided through the elongated tubular body portion 121 and nozzle tip 122 of the nozzle tube 12 to the outside of the inside wall of the spray tube 11. When the high speed flow of compressed air of fluid is flowing through the connection area between the elongated tubular body portion 121 and the nozzle tip 122 of the nozzle tube 12, an eccentric force is produced, causing rotation of the nozzle tube 12 relative to the spray tube 11, and therefore the output flow of compressed air or fluid is forced out of the orifice 111 of the spray tube 11, forming a mist of fine drops of fluid (in the case that compressed fluid is forced through the intake port 22 into the barrel 21) for cleaning things. Further, the spray tube 11 is a hard or rigid tube (made of metal, for example, aluminum, or hard plastics), having high structural strength and toughness. Because the elongated tubular body portion 121 of the nozzle tube 12 is relatively longer than the nozzle tip 122 and supported in the first bearing 14, the reinforcing tube 13 and the second bearing 15, the nozzle tube 12 is forced to rotate at a high speed stably during flowing a high speed flow of compressed air or fluid therethrough. By means of the first bearing 14 and the second bearing 15 to support the two distal ends of the elongated tubular body portion 121 and the reinforcing tube 13 to surround the major part of the elongated tubular body portion 121, the nozzle tube 12 does not break or deform during its high speed rotation, assuring high durability.

[0021] Referring to FIG. 6, in another application example of the first embodiment of the present invention, the barrel 21 of the spray gun 2 has a water inlet 212 cut through the peripheral wall thereof, and a water supply unit 3 is connected to the water inlet 212 for supplying water to the inside of the barrel 21. The water supply unit 3 has a top cap 33, a connection tube 31 perpendicularly extended from the top cap 33 and connected to the water inlet 212 of the barrel 21, a control valve 32 mounted in the connection tube 31 for controlling the water passage defined in the connection tube 31 in communication with the water in the water supply unit 3, and a handle 321 connected to the control valve 32 and biasable to open/close the control valve 32. When the user pressed the control lever 23 of the spray gun 2, a high speed flow of compressed air is forced into the barrel 21 through an intake port 22 and then guided through the elongated tubular body portion 121 and nozzle tip 122 of the nozzle tube 12 to the outside of the inside wall of the spray tube 11. When the high speed flow of compressed air of fluid is flowing through the barrel 21, a Venturi effect is produced, causing water to be sucked upwards from the water supply unit 3 into the barrel 21 and carried by the high speed flow of air through the nozzle tube 12 toward the outside of the spray tube assembly 1. When the high speed flow of air and water mixture is flowing through the connection area between the elongated tubular body portion 121 and the nozzle tip 122 of the nozzle tube 12, an eccentric force is produced, causing rotation of the nozzle tube 12 relative to the spray tube 11, and therefore a very fine water mist is sprayed out of the orifice 111 of the spray tube 11 for application.

[0022] FIG. 7 is an exploded view of a spray tube assembly 1 for rotary spray gun in accordance with a second embodiment of the present invention. Similar to the aforesaid first embodiment, the spray tube assembly 1 according to this second embodiment is comprised of a spray tube 11, a nozzle tube 12, a reinforcing tube 13, a first bearing 14, a second bearing 15 and a gasket ring 16. This second embodiment eliminates the fitting 113 of the aforesaid first embodiment (see FIG. 2) and has an inner thread 1123 formed in the connection portion 112 of the spray tube 12 for threading onto the outer thread 2111 around the periphery of the front connection portion 211 of the barrel 21 of a spray gun 2. Further, the spray tube 11 has two longitudinal locating ribs 114 protruded from the inside wall at two opposite sides, and an inside annular flange 115 protruded from the inside wall near the orifice 111. The inside annular flange 115 defines a center hole 1151. Further, the nozzle tube 12 has an outer thread 1211 extending around the periphery of one end of the elongated tubular body portion 121 remote from the nozzle tip 122. Further, the reinforcing tube 13 has two longitudinal locating grooves 131 located on the periphery at two opposite sides and respectively coupled to the longitudinal locating ribs 114 of the spray tube 11, and two annular locating grooves 132 respectively located on the inside of the front and rear ends thereof for accommodating the first bearing 14 and the second bearing 15 respectively. Further, the gasket ring 16 has a shank 161 perpendicularly extended from one side thereof for insertion into the second bearing 15 to hold the second bearing in place 15, and an inner thread 1611 defined in the shank 161 for threading onto the outer thread 1211 of the nozzle tube 12.

[0023] During installation of the spray tube assembly 1, set the first bearing 14 and the second bearing 15 in the two annular locating grooves 132 of the reinforcing tube 13 and then sleeve the first bearing 14, the reinforcing tube 13, the second bearing 15 and the gasket ring 16 onto the elongated tubular body portion 121 of the nozzle tube 12 in proper order, and then thread the inner thread 1611 of the gasket ring 16 onto the outer thread 1211 of the nozzle tube 121, and then aim the nozzle tip 122 of the nozzle tube 12 at the connection portion 112 of the spray tube 11 axially and insert the nozzle tube 12 into the spray tube 11 to insert the nozzle tip 122 of the nozzle tube 12 through the center hole 1151 of the inside annular flange 115 of the spray tube 11 and to force the two longitudinal locating grooves 131 of the reinforcing tube 13 into engagement with the two longitudinal locating ribs 114 of the spray tube 11 respectively. Thus, the pray tube 11, the nozzle tube 12, the reinforcing tube 13, the first bearing 14, the second bearing 15 and the gasket ring 16 are assembled, forming the desired spray tube assembly 1.

[0024] After connection of the spray tube assembly 1 to the barrel of a spray gun (not shown), the user can operate the control lever of the spray gun to let a flow of compressed water go through the barrel into the nozzle tube 12. When a high speed flow of compressed water is flowing through the connection area between the elongated tubular body portion 121 and the nozzle tip 122 of the nozzle tube 12, an eccentric force is produced, causing rotation of the nozzle tube 12 relative to the spray tube 11, and therefore the output flow of compressed water is forced out of the orifice 111 of the spray tube 11, forming a fine water mist for application. Because the elongated tubular body portion 121 of the nozzle tube 12 is relatively longer than the nozzle tip 122 is supported in the first bearing 14, the reinforcing tube 13 and the second bearing 15 and because the reinforcing tube 13 has its two longitudinal locating grooves 131 located on the periphery at two opposite sides and respectively coupled to the longitudinal locating ribs 114 of the spray tube 11, the first bearing 14, the reinforcing tube 13 and the second bearing 15 give excellent support to the nozzle tube 12, allowing smooth rotation of the nozzle tube 12 at a high speed relative to the spray tube 11, and therefore the nozzle tube 12 does not break or deform during its high speed rotation, assuring high durability.

[0025] As stated above, a fitting 113 that defines therein an inner thread 1131 can be tightly press-fitted into the circular mounting hole 1121 of the connection portion 112 of the spray tube 11 for threading onto the outer thread 2111 of the barrel 21 of a spray gun 2. Alternatively, an inner thread 1123 can be directly made in the connection portion 112 of the spray tube 11 for threading onto the outer thread 2111 of the barrel 21 of a spray gun 2. It is to be understood that other detachable mounting techniques may be employed for detachable connection between the spray tube 11 and the barrel 21 of a spray gun 2.

[0026] In either of the aforesaid two embodiments of the present invention, the first bearing 14, the reinforcing tube 13, the second bearing 15 and the gasket ring 16 are sleeved onto the nozzle tube 12 and then inserted with the nozzle tube 12 into the spray tube 11, forming a modularized structure of spray tube assembly for quick connection to the barrel 21 of a spray gun 2 in a detachable manner. This design of modularized spray tube assembly 1 facilitates installation and maintenance. When a repair work is necessary, the connection portion 112 of the spray tube 11 can be directly disconnected from the barrel 21 of the spray gun 2, allowing dismounting of the component parts for examination and further replacement or repair work.

[0027] In conclusion, the invention provides a spray tube assembly for rotary spray gun, which has advantages and features as follows:

1. The first bearing 14, the reinforcing tube 13, the second bearing 15 and the gasket ring 16 are sleeved onto the nozzle tube 12 and then inserted with the nozzle tube 12 into the spray tube 11, forming a modularized structure of spray tube assembly 1 for quick connection to the barrel 21 of a spray gun 2 in a detachable manner. Thus, the invention facilitates installation and maintenance.

2. The invention uses the first bearing 14, the reinforcing tube 13 and the second bearing 15 to give excellent support to the elongated tubular body portion 121 of the nozzle tube 12, allowing smooth rotation of the nozzle tube 12 at a high speed relative to the spray tube 11, and therefore the nozzle tube 12 does not break or deform during its high speed rotation, assuring high durability.

3. The gasket ring 16 is abutted against the outer side of the first bearing 14 and kept in friction engagement with the inside wall of the connection portion 112 of the spray tube 11 tightly, securing the second bearing 15 to the annular step 1122 in the circular mounting hole 1121 of the connection portion 112 of the spray tube 11 firmly and avoiding water leakage and preventing accumulation of leaked water in the space within the spray tube 11 and outside the reinforcing tube 13.

[0028] A prototype of spray tube assembly for rotary spray gun has been constructed with the features of FIGS. 1∼8. The spray tube assembly for rotary spray gun functions smoothly to provide all of the features disclosed earlier.

[0029] Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.

Claims

1. A spray tube assembly connected to a barrel of a spray gun used in a rotary spray gun, comprising:

a spray tube, said spray tube having an orifice located on one end thereof and a connection portion located on an opposite end thereof, said connection portion defining therein a circular mounting hole for connection to the barrel of said spray gun;

a nozzle tube mounted in said spray tube, said nozzle tube having an elongated tubular body portion and a nozzle tip extended from a front end of said elongated tubular body portion an opposite end thereof terminating in at an angle and suspending inside said spray tube in proximity to said orifice;

a reinforcing tube mounted inside said spray tube around said elongated tubular body portion of said nozzle tube;

a first bearing attached to one end of said reinforcing tube around one end of said elongated tubular body portion of said nozzle tube near said nozzle tip to support rotation of said nozzle tube relative to said spray tube;

a second bearing attached to an opposite end of said reinforcing tube around an opposite end of said elongated tubular body portion of said nozzle tube near said connection portion to support rotation of said nozzle tube relative to said spray tube; and

a gasket ring attached to one side of said second bearing opposite to said reinforcing tube and kept in contact with the inside wall of said spray tube near said connection portion.

2. The spray tube assembly as claimed in claim 1, further comprising a fitting fixedly mounted in the circular mounting hole of said connection portion of said spray tube, said fitting having an inner thread for mounting.

3. The spray tube assembly as claimed in claim 1, wherein said spray tube is an aluminum tube.

4. The spray tube assembly as claimed in claim 1, wherein fitting is made of cotton knit fabric.

5. The spray tube assembly as claimed in claim 1, wherein said connection portion of said spray tube comprises an inner thread formed in said circular mounting hole.

6. The spray tube assembly as claimed in claim 1, wherein said spray tube comprises two longitudinal locating ribs protruded from the inside wall thereof at two opposite sides; said reinforcing tube comprises two longitudinal locating grooves located on the periphery thereof at two opposite sides and respectively coupled to the longitudinal locating ribs of said spray tube.

7. The spray tube assembly as claimed in claim 1, wherein said spray tube comprises an inside annular flange protruded from the inside wall thereof near said orifice, said inside annular flange defining a center hole for the passing of said nozzle tip of said nozzle tube.

8. The spray tube assembly as claimed in claim 1, wherein said nozzle tube comprises an outer thread extending around the periphery of one end thereof remote from said nozzle tip; said gasket ring comprises a shank perpendicularly extended from one side thereof for insertion through said second bearing, and an inner thread defined in said shank for threading onto the outer thread of said nozzle tube.

9. The spray tube assembly as claimed in claim 1, wherein said reinforcing tube comprises two annular locating grooves respectively located on the two distal ends thereof for accommodating said first bearing and said second bearing respectively.

Drawing