Improved pressure gauge more especially for use with pneumatic tyres

摘要

194,048. Bentley, D. T. Jan. 4, 1922. Pneumatic-tyre pressure gauges; piston and spring pressure gauges with signal and alarm arrangements.-A construction is described of the type in which the gauge is set to any of a range of pressures and when this pressure is exceeded a whistle is sounded. The body 5 is formed with a chamber 15 over which takes a cap 7. A hollow screw plug 12 forms a seat for a valve 14. A duct 16 leads from the chamber 15 to an. annular groove 17 on a screwed plug 18, the groove communicating by radial passages 19 with a bored out portion of the plug. The body 5 is formed with a tubular extension 21 having a longitudinal slot 28 from which branch transverse notches. A tube 26 closed at one end which is knurled at- 27 works inside the tube 21 and surrounds a spring 25 the other end of which extends into a thimble 24 located in the bore of the plug 18. A central extension 23 on this part acts as a valve and normally closes the radial passages 19. When this valve is opened the fluid passes by a passage 30 to a whistle 31. In use, the tube 26 is first turned so that the pin 29 lies in the longitudinal slot. The tube is then moved lengthways until the spring has been given the required compression, the pin 29 then being turned into the required graduated notch. The cap 7 is then placed over the valve tube the latter raising the valve 14. When the pressure fluid has been admitted through the tube 6 and valve to the required extent the pressure acting through the duct moves back the thimble and blows the whistle. In a modification the valve is depressed with and connection made with tyre valve stem by a screened union.