Patent GB-221207-A (GB)
Title: Improvements in and relating to recording devices for measuring instruments and moreparticularly electric meters
IPC: G01R13/00
Filed: 1924-08-22
Abstract: 221,207. Landis et Gyr Soc. Anon. Aug. 28, 1923, [Convention date]. Recording by distinctive marks.-In intermittently recording devices particularly for use in electricity measuring instruments wherein the record is made in the form of lines on the paper strip, the lines are produced by the momentary pressure, of the paper strip and a copying band, between a member or drum rotatable at a speed proportional to that of the moving element of the instrument and a ruler-shaped member or bar operated at the end of each measuring period. In the forms shown the bar receives its movement from an independent source of power. As shown in Fig. 1, the moving element 14 of the instrument imparts movement, through a shaft 12, friction clutch 13, and the planet wheel 3 of a differential gear 3 .. 5, to a shaft 6 carrying a drum 1 provided with a raised helical surface 2. The wheel 4 of the differential is connected through gearing 15 to a separate source of power (not shown) and drives a shaft 16 provided with a crank 17 to which is pivoted a link 18 that engages a cross rod 20 attached to a pair of pivoted arms 19. A ruler-shaped member or bar 21 is mounted between the arms 19 and has an edge 21<1> extending the length of the drum. Surrounding the bar 21 is a copying ribbon 23 supported by means of rollers 22 mounted on the arms 19. The record-strip passes between the drum 1 and the copying-ribbons 23. During the measuring period when the drum is being rotated by the element 14 the shafts 15, 16 remain at rest. At the end of the period the separate source of power is switched in by a clockwork mechanism to effect the rotation of the shaft 16 to cause the bar 21 to press the record strip against the surface 2 whereupon the shaft 15 is effective to return the drum to its normal position shown in Fig. 1, the wheel 4 being adapted to be driven at a greater speed than the wheel 5. The spindle 6 is provided with a graduated drum 7 which indicates the setting at any moment, the maximum value during the preceding periods being indicated by a spring controlled drum 8 which is loose on the spindle 6 and is adapted to be driven by the drum 7. The feed of the record strip and copying-ribbon may be effected in any known manner; as shown in Fig. 2, the copying- ribbon is fed by means of a ratchet wheel 32 on one of rollers 22 and a spring controlled pawl 27 which is provided with an inclined surface 31 adapted to be engaged by a projection on the arm 19. In a modification the restoring of the drum 6 to normal position is effected by means associated with the ruler shaped member 21, the differential gear being dispensed with. The means comprises a toothed sector 39, Fig. 3, pivoted to one of the arms 19 and having a pawl 41 co-operating with a surface 42 so as to effect the engagement of the sector with a pinion 33 on the return stroke of the arms 19. The pinion 33 is connected to the drum 1 through a friction clutch and spring 37. The surface may extend like a band 2<1> around the drum or the drum may be replaced by a strip of rectangular section twisted about its longitudinal axis and rotatable. about said axis.