Low-flow emitter

Abstract

A low-flow emitter includes a first housing and a second housing. The first housing includes a first thread portion, and a first passage defined in the first thread portion. The second housing includes a second thread portion, and a second passage defined in the second thread portion corresponding with the first thread portion in a thread connection. Part of the thread connection between the first and second housings is a loose fitting thread connection. A spiral passage is formed along the loose fitting thread connection between the first and second housings. Water flow rate is able to be controlled by a rotation of the first housing with respect to the second housing.

What is claimed is: 
     
         1 . A low-flow emitter comprising:
 a first housing including a thread bore and a first thread portion, the first thread portion is formed on the thread bore; the first thread portion including a first thread section and a second thread section;   a second housing including a thread axle and a second thread portion, the second thread portion is formed on the thread axle; the second thread portion including a third thread section corresponding with the first thread section of the first thread portion of the first housing, and a fourth thread section corresponding with the second thread section of the first thread portion of the first housing; the second housing connecting the first housing while the fourth thread section of the second thread portion of the second housing engaging with the second thread section of the first thread portion of the first housing;   a spiral passage defined between the third thread section of the second thread portion of the second housing and the first thread section of the first thread portion of the first housing;   a first passage formed on the first housing and communicating with the spiral passage; and   a second passage formed on the second housing and communicating with the spiral passage, and the spiral passage via an orifice radially formed on the second thread portion;   wherein the thread bore defines a diameter which increases in a direction away from the first passage;   wherein the thread axle defines a diameter which increases in a direction away from the first passage;   wherein the water flows from the second passage through the orifice to the spiral passage, and then enters the first passage for water distribution.   
     
     
         2 . The low-flow emitter as claimed in  claim 1 , wherein the thread bore defines an end communicating with the first passage. 
     
     
         3 . The low-flow emitter as claimed in  claim 1 , wherein the first and second thread sections are formed on the first thread portion of the first housing and connected with each other; the third and fourth thread sections are formed on the second thread portion of the second housing and connected with each other. 
     
     
         4 . The low-flow emitter as claimed in  claim 3 , wherein the third thread section of the second housing defines a crest with a crest height, and the first thread section of the first housing defines a root with a thread depth; the crest height of the third thread section of the second housing is less than the thread depth of the first thread section of the first housing, and the spiral passage is formed between the crest of the third thread section of the second housing and the root of the first thread section of the first housing. 
     
     
         5 . The low-flow emitter as claimed in  claim 4 , wherein the thread depth of the first thread section of the first housing equals to a thread depth of the second thread section of the first housing; the thread depth of the second thread section of the first housing equals to a height of a crest of the fourth thread section of the second housing. 
     
     
         6 . The low-flow emitter as claimed in  claim 1 , wherein the third thread section of the second housing defines a crest with a crest height, and the first thread section of the first housing defines a root with a thread depth; the crest height of the third thread section of the second housing is less than the thread depth of the first thread section of the first housing, and the spiral passage is formed between the crest of the third thread section of the second housing and the root of the first thread section of the first housing. 
     
     
         7 . The low-flow emitter as claimed in  claim 6 , wherein the thread depth of the first thread section of the first housing equals to a thread depth of the second thread section of the first housing; the thread depth of the second thread section of the first housing equals to a height of a crest of the fourth thread section of the second housing. 
     
     
         8 . The low-flow emitter as claimed in  claim 1 , wherein the first housing includes an end member, a circumference member bordering a periphery of the end member, a tubular head extending from an exterior face of the periphery of the end member in a direction away from the end member, and the thread bore extending from an interior face of the periphery of the end member in a direction away from the end member; the first passage is formed in the tubular head. 
     
     
         9 . The low-flow emitter as claimed in  claim 8 . wherein the second housing includes a flange retaining against an end of the thread bore of the first housing; the second thread portion extends from the flange in a direction away from the flange. 
     
     
         10 . The low-flow emitter as claimed in  claim 9 , wherein the width of the spiral passage is adjusted by rotation of the first housing, whereupon the second thread section of the first thread portion of the first housing move relative to the fourth thread section of the second thread portion. 
     
     
         11 . The low-flow emitter as claimed in  claim 1 , wherein the second housing includes a flange retaining against an end of the thread bore of the first housing; the second thread portion extends from the flange in a direction away from the flange. 
     
     
         12 . The low-flow emitter as claimed in  claim 11 , wherein the width of the spiral passage is adjusted by rotation of the first housing, whereupon the second thread section of the first thread portion of the first housing move relative to the fourth thread section of the second thread portion. 
     
     
         13 . The low-flow emitter as claimed in  claim 1 , wherein the width of the spiral passage is adjusted by rotation of the first housing, whereupon the second thread section of the first thread portion of the first housing move relative to the fourth thread section of the second thread portion.