GB478551A - Improvements in date indicators - Google Patents

Abstract

478,551. Date-indicators. JISKRA, Z. March 24, 1937, No. 8611. Convention date, March 30, 1936. [Class 106 (iv)] A date-indicator comprises four discs, Figs. 1-4, which carry indicators of the day name, month name, date figure and units figure of the year number, the discs having peripheral teeth which are engaged by an actuating pawl Z, Fig. 9. The discs shown in Figs. 1-3 have apertures for exposing the data on the discs of Figs. 2-4. A fifth disc, Fig. 5, indicates " forenoon " and " afternoon " through an aperture P<4>, Fig. 9, in the back of the casing. The pawl Z is carried by a lever Y, allowed to rock clockwise suddenly every twelve hours. The direction of this rocking is anticlockwise in Figs. 1-6. The pawl Z is spring-pressed against a shaped gap M, Fig. 6, in a fixed plate, the end of the pawl being wide enough to engage the teeth of all the superposed discs, Figs. 1-5. At midday, the pawl engages a shallow tooth 2 of the disc of Fig. 5 and is thus held out of contact with the other discs and advances this disc only. At midnight, a deep tooth 3 on this disc allows the pawl to advance this disc, the day-name disc, Fig. 1, and the date-figure disc, Fig. 3. This last disc advances through a smaller angle than the other two because the portion fg of the gap M in the fixed plate masks the teeth of the said date-figure disc. The date-figure disc has long teeth 30, 31, 1, 2 in operative position at the end and beginning of a month so that this disc is advanced the necessary extra steps at the end of a short month unless the long teeth are masked by the long teeth 1 of the monthname disc, Fig. 2. The teeth of these two discs are so arranged that the dates are correctly altered every day throughout the year. The date figure, in addition to the month name, for the 1st of each month (and also for the 2nd March) is shown on the month-name disc, being advanced on both the first and second days of the month (and also on the 3rd March). At the end of February in a leap year, a high tooth 3 on the year number disc, Fig. 4, is in position to co-operate with the teeth of the other discs to cause 29th February to be indicated.