GB517527A - Improvements in gas meters - Google Patents

Abstract

517,527. Gas meters. WILSON GAS METERS, Ltd., G., and POOLE, D. C. E. July 21, 1938, No. 21632. [Class 27] In dry gas meters in which the operation of the meter is automatically stopped after the meter has passed a predetermined quantity, means is associated with the pointer door or' cover-plate whereby, when this is closed, the stop mechanism is locked against alteration of the setting. A differential gear is introduced between the drive shaft 7 and the pointer shaft 2, and one element of this gear is automatically held stationary when the pointer door is locked. The differential consists of a crown wheel 13, fixed to the shaft 2, a crown wheel 14, unitary with a pinion 15, both rotating freely about the shaft 2, and planet wheels 17, carried by a pinion 18, driven by a worm 6, on the shaft 7. When the door 12 is locked by a detent 16, which is pressed by a spring 22; to a position behind an inclined stop 23, the detent 16 acts as a pawl holding the pinion 15 and wheel 14 stationary and the drives qf the shaft 2, and its associated valve-operating rod 3, is effected through the worm 6, pinion 18, planets 17, and crown 13. On screwing a key on to the end of detent barrel 19 to raise the detent 16 and unlock the door 12, the pinion 15 becomes free to rotate and the pointer 4 can be adjusted to any required position. The incline 23 renders the door selflocking on closure.