1. Field of the Invention
The present invention relates to spray nozzles and more particularly, to a rotary spray nozzle, which pressurizes an intake flow of compressed air and fluid to enhance rotation of a bent nozzle tube.
2. Description of the Related Art
A high-pressure spray gun for aerated pressure washing employs the venture effect to enhance the pressure of a flow of compressed gas and fluid passing through a spray nozzle, causing rotation of a bent nozzle tube. This nozzle tube rotating method uses an outer sleeve to rotate the bent nozzle tube. Thus, the spray nozzle has a large dimension and heavy weight, and requires much dynamic energy to rotate the outer sleeve and the bent nozzle tube. Further, the pressure produced subject to the venture effect according to this prior art design is limited. The pressure of the sprayed flow of fluid may be insufficient to achieve optimal aerated pressure washing.
The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a rotary spray nozzle, which has compact size and light weight characteristics, and is practical for use in a spray gun to enhance the aerated pressure washing efficiency of the spray gun.
To achieve this and other objects of the present invention, a rotary spray nozzle comprises a barrel, a coupling tube set comprising a coupling tube rotatably supported in axle bearings inside the barrel and defining therein a flow passage, a pressure tube connected to one end of the barrel and defining therein a gas intake passage that is kept in communication with the flow passage of the coupling tube and reduces gradually in direction toward the flow passage of the coupling tube, and a bent nozzle tube connected to one end of the coupling tube remote from the pressure tube for free rotation with the coupling tube relative to the barrel and defining therein a spiral flow passage in communication with the flow passage of the coupling tube.
Referring to
The barrel 1 comprises opposing first connection end 11 and second connection end 12, and an inner thread 111 on an inner perimeter of the first connection end 11.
The coupling tube set 2 comprises a coupling tube 21, which comprises opposing first mating end 211 and second mating end 212, an inner thread 214 on an inner perimeter of the second mating end 212 and a flow passage 213 in communication between the first mating end 211 and the second mating end 212, two axle bearings 22 mounted around the coupling tube 21, a locknut 8 threaded onto the first mating end 211 of the coupling tube 21, an intermediate bush 23 mounted around the coupling tube 21 and stopped between the two axle bearings 22, two end bushes 6 respectively sleeved onto the first mating end 211 and the second mating end 212 and mounted with the coupling tube 21, the two axle bearings 22 and the intermediate bush 23 in the barrel 1 to have the end bush 6 at the second mating end 212 be firmly secured to the inside of the second connection end 12 of the barrel 1, and a retainer 7, for example, a C-shaped retaining ring 7 fastened to the second mating end 212 and stopped between an inside part of the second connection end 12 of the barrel 1 and the associating end bush 6 to prohibit the coupling tube 21 of the coupling tube set 2 from escaping out of the barrel 1.
The pressure tube 3 comprises opposing gas inlet end 31 and gas outlet end 32, a gas intake passage 33 in communication between the gas inlet end 31 and the gas outlet end 32, and an outer thread 321 on the outer perimeter of the gas outlet end 32. The outer thread 321 is threaded into the inner thread 111 of the barrel 1. Further, the gas intake passage 33 is a tapered flow passage gradually reducing in direction from the gas inlet end 31 toward the gas outlet end 32. The gas outlet end 32 is connected to the first connection end 11 of the barrel 1. The gas intake passage 33 is kept in communication with the flow passage 213 of the coupling tube 21 of the coupling tube set 2. Further, a gas chamber 5 is defined between the gas outlet end 32 of the pressure tube 3 and the first mating end 211 of the coupling tube 21 of the coupling tube set 2.
The bent nozzle tube 4 comprises a connector 41 having an outer thread 411 threaded into the inner thread 214 of the coupling tube 21, a nozzle head 42 obliquely extended from the connector 41, a spiral flow passage 43 defined in the nozzle head 42 in communication with the flow passage 213 of the coupling tube 21 of the coupling tube set 2.
Referring to