| 摘要 |
1,224,649. Blasting. PANGBORN CORP. 11 June, 1968 [13 June, 1967], No. 27747/68. Heading B3D. [Also in Division B8] A metal treating device, e.g. for cleaning by abrasive or peening by shot, comprises a treating nozzle, first pressure means connected to said treating nozzle, a treating media feed chamber communicating with said nozzle, a supply chamber communicating with said feed chamber, a metering chamber communicating with said supply chamber, said first pressure means being connected for pressurizing said feed and said supply chambers, valve means between said feed and supply chambers and between said supply and metering chambers, and second pressure means for controlling the actuation of said valve means. Treating apparatus comprises a feed hopper 20 for abrasive or shot, a metering chamber 18, a supply chamber 16 and a feed chamber 14, with interposed valves 28, 22, 24. A pressure source 26 provides air pressure (a) for a direct pressure nozzle 12 communicating with the feed chamber 14, (b) for constant pressurization of chamber 14 and (c) for intermittent pressurization, under control of a valve 38, of chamber 16. A pressure source 30 powers valves 28, 22, 24. A switch 32 mounted in chamber 14 is actuated when the level of treating media is low, energizing a timer to give the following cycle :- (1) Valve 38 actuated to pressurize chamber 16; (2) Valves 24, 28 opened, allowing media in chamber 16 to pass into chamber 14 and media from hopper 20 to fill chamber 18; (3) Valves 24, 28 closed; (4) Valve 38 actuated to put chamber 16 to atmosphere through port 42; (5) Valve 22 opened, allowing media in chamber 18 to pass into chamber 16; (6) Valve 22 closed. The capacity of chamber 18 is less than that of chamber 16 and of chamber 14 so that valves 22, 24 do not close on media. Valve 28 is a normally closed spring loaded valve which shuts off media flow in the event of a failure. The hopper 20 has compartments storing different types of media, control valves 44 permitting selection. Each valve 22, 24 comprises a conical skirt 66 loosely seated on a ball 64 at the end of the piston-rod 60 of a pneumatic cylinder 56. A washer 68 on the rod 60 lies between an internal shoulder 70 on the skirt and a limit ring 72. |
