| 摘要 |
<p>480,226. Pneumatic tyres. MICHELIN & CIE. May 7, 1937, No. 13157. Convention date, May 7, 1936. [Class 144 (i)] A device for indicating tyre-deflation comprises two diaphragm valves each subject on one side to the tyre-pressure and at the other side to a slightly greater pressure, the first valve opening on a predetermined fall of pressure in the tyre to control the opening of the second valve whereby an audible signal is actuated. In the form shown, compressed air is supplied through the nozzle 1 to a chamber 41 which communicates through passage 6 with space 43 surrounding the signal-operating valve A3. The upper end of the chamber 41 is fitted with a spring-loaded diaphragm 3 having a small aperture 4 leading to the chamber S1 which opens to atmosphere by vent 101. The air admitted to chamber 41 lifts the diaphragm 3 to close the aperture 4, by contact with a plug 5, and then passes through port 6 to space 43, passage 10, space 42, and tyre-connecting nipple 7. On predetermined fall of pressure in the tyre, the diaphragm 3 is forced from the plug 5 thereby opening the space 43 to atmosphere through the port 101. The pressure in the tyre then operates, through port 11, to lift membrane 53 surrounding the valve A3 so that air escapes from the tyre through port 12, which is of larger cross-section than port 11, and funnel 8 to atmosphere. The resultant vibration of the membrane 53 at the port 12 gives an audible signal until the reduced tyrepressure is insufficient to lift the membrane. To restrict escape of air from an inflated tyre during fitment to replace the deflated tyre, a valve-device C is provided to connect the space 43 with the tyre and hold the membrane 53 to its seat, thereby shutting-off communication with the venting-space 41. The valve C comprises a spring-loaded head 13 which is pressed off its seat, by means of a button 15, to open the air-circuit 7, 17, 18 and space 43. Specification 445,643, [Group XXIX], is referred to.</p> |
