US 11,654,446 B2
Device for adjusting air pressure of spray gun and method for the same
Wan Pao Chen, Changhua County (TW)
Assigned to Hui Bao Enterprise Co., Ltd., Changhua County (TW)
Filed by HUI BAO ENTERPRISE CO., LTD., Changhua County (TW)
Filed on Aug. 17, 2020, as Appl. No. 16/994,981.
Claims priority of application No. 109124085 (TW), filed on Jul. 16, 2020.
Prior Publication US 2022/0016652 A1, Jan. 20, 2022
Int. Cl. B05B 7/12 (2006.01); B05B 12/00 (2018.01); B05B 7/24 (2006.01)
CPC B05B 7/12 (2013.01) [B05B 12/002 (2013.01); B05B 7/2478 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A spray gun having a device for adjusting air pressure, comprising:
a spray gun body having a trigger and a grip, a main path formed in the spray gun body, a grip path formed in the grip, and a sub path in open communication with the grip path, the sub path having a first opening at a first end of the sub path in a direct communication with the grip path and a second opening at an opposite end of the sub path;
a trigger valve connected to the spray gun body and contacting the trigger, the trigger valve dividing the main path into a front path and a rear path, the front path being in communication with a nozzle of the spray gun body, the rear path being located at a rear end of the trigger valve and being in communication with the sub path, a first chamber and a second chamber being respectively formed in the rear path in a spaced apart relationship with the grip path;
an air adjustment valve located in the first and second chambers, the second chamber being located at the rear end of the trigger valve and the first chamber being located above and in communication with the second opening of the sub path, the air adjustment valve including a longitudinally extending tube configured with a radial hole defined radially therethrough in alignment with the second opening of the sub path, and a movable part and a spring being located at a first end of the tube adjacent to the second chamber, the movable part having an air passage extending longitudinally therethrough and being longitudinally slidably displaceable against a bias force of the spring by air pressure in the second chamber, the adjustment valve further including an adjustment member having a distal end connected to an opposing second end of the tube and being manually operable to adjust a longitudinal distance between the distal end of the adjustment member and a corresponding end to the movable part, an air flow path through the air passage of the movable part being closed responsive to the corresponding end thereof contacting the distal end of the adjusting member to limit the air pressure in the second chamber, and the movable part being reversibly displaced by the spring responsive to the air pressure in the second chamber being reduced and thereby regulate the air pressure supplied to the second chamber, wherein the manually adjusted longitudinal distance between the distal end of the adjustment member and the corresponding end of the movable part sets a selected regulated pressure of air supplied to the second chamber for supplying the selected predetermined regulated pressure to the front path.