Weft insertion pump for water jet loom

Abstract

A weft insertion pump for a water jet loom includes a pump housing, a water storage chamber forming cylinder, a plunger, discharge and suction ports, a water storage chamber, a discharge-side check valve, a suction-side check valve and a stop member. The suction-side check valve includes a valve body, a valve seat member having a valve surface and a stop member. The stop member is formed with a plurality of guide walls which are spaced at an angular interval and configured to slidably guide the valve body in an axial direction of the stop member. Communication passages are formed in a circumferential direction of the stop member between any two adjacent guide walls. An annular groove is formed in the valve seat member so as to surround and be continuously connected to the valve surface for providing fluid communication between the communication passages.

What is claimed is: 
     
         1 . A weft insertion pump for a water jet loom comprising:
 a pump housing;   a water storage chamber forming cylinder disposed within the pump housing;   a plunger slidably received in the water storage chamber forming cylinder;   a discharge port formed in the pump housing and connected to a weft insertion nozzle;   a suction port formed in the pump housing and connected to a water tank;   a water storage chamber formed between the suction port and the discharge port;   a discharge-side check valve interposed between the water storage chamber and the discharge port; and   a suction-side check valve interposed between the water storage chamber and the suction port, the suction-side check valve including:
 a valve body having a spherical shape; 
 a valve seat member having a valve surface, the valve seat member through which a suction passage is formed; and 
 a stop member having a cylindrical shape and including a stop part configured to regulating moving distance of the valve body away from the valve surface of the valve seat member, the stop member formed with a plurality of guide walls spaced at an angular interval, the guide walls configured to slidably guide the valve body in an axial direction of the stop member, any two adjacent guide walls between which communication passages are formed in a circumferential direction of the stop member, the communication passages through which water from the suction passage is flowed, 
   wherein an annular groove is formed in the valve seat member so as to surround and be continuously connected to the valve surface for providing fluid communication between the communication passages.   
     
     
         2 . The weft insertion pump for the water jet loom according to  claim 1 , wherein the annular groove has an outer peripheral edge and each communication passage has an outer peripheral edge, the outer peripheral edge of the annular groove and the outer peripheral edge of the communication passage are in continuity with each other in the axial direction of the stop member. 
     
     
         3 . The weft insertion pump for water jet loom according to  claim 1 , wherein the annular groove is formed by providing an annular member between the valve seat member and the stop member.