Pressure-indicating device for use with pneumatic tires

291,230. Little, C. W. G. May 27, 1927. Pneumatic tyre pressure gauges.-Comprises a gauge, a carrier therefor permanently mounted on the felloe or rim and a member to actuate said gauge contained within said carrier and subject to the pressure of the air tube and to the opposing action of a spring which is stressed by the action of mounting the gauge on the carrier. A tube 15, Fig. 1, passes through the rim 12 and felloe 11 of the wheel and at one end 16 is flanged and provided with a recess 17. A nut 22 secures the tube in position. The tube houses a gauge actuator 23 surrounded by a spring 31. The actuator 23 is hollow being closed at one end and screwed into the head 25. Integral with the head 25 is a pressure plate 26 bearing against the inner tube 14. The head is provided with a slot 27 through which a pin 28 secured to the tube 15 passes. A screw-threaded collar 29 at the upper end of the tube 23 receives a screwed rod 48, Fig. 4, connected to a two armed lever 40 mounted on a pivot 41, one arm of which is formed as a rack gearing with a pinion 46 on a pointer spindle, while the other arm works between stops 43, 44. The spring 31 bears at one end against the head 27 and at the other against a cup washer 32. The gauge casing has a tubular extension 38 which is screwed into the tube 15 to tension the spring 31, the rod 48 being at the same time screwed into the collar 29 the threads on extension and rod being of the same pitch. In a modified construction, Fig. 5, the pressure plate 26, head 25, and pin 27 are omitted and a part 25 of the same diameter as the gauge actuator substituted therefor, a squared extension 26b receiving the bent over and recessed ends of a flat spring member through which the reduced part at the end of the tube 15 is passed and secured by a nut. The sides of the plate spring 55 are bent downwards and lugs 62 provided to form a trough to receive the bent over ends which are secured to the part 25 by a nut 26. This construction enables the bulk of the pressure of the inner tube to be taken by the spring presser plate 57, and the fitting of a lighter spring 31.