GB1432636A - Perpetual calendar - Google Patents

Abstract

1432636 Perpetual calendars L D SPICER 15 Sept 1973 43407/73 Heading G3T A perpetual calendar comprises three coaxial relatively rotatable truncated-cone shaped members 28, 36 and 50, member 28 bearing month name abbreviations selectively viewable through slots 48 in member 36 which bears day of the month indicia selectively viewable through a window 53 in member 50 which bears day of the week indicia above window 53. The range of relative rotation of the member 28, 36 is limited to 90 degrees or less by a lug 54 on member 36 engaging a recess 56 in the edge 58 of member 28. Secured by nuts 68 to member 28 is a ring 63 bearing areas around its periphery with a series of seven colours repeated five times, every fifth area being extended radially inwardly of the remainder. Mounted on member 28 is a cylinder 70 bearing indicia Fig. 10 (not shown) which represent millenia of the Julian and Gregorian calenders, and which are selectively viewable through a slot 84 in a rotatable casing 74. A cylindrical portion of casing 74 bears Gregorian calender centuries indicia selectively viewable through a slot 92 in a tubular member 86. A horizontal flange 82 integral with casing 74 bears Julian calender centuries indicia which are selectively viewable through a hole 90 in a decade disc 88 and a transparent year disc 94. The spacing of the year numerals on disc 94 correspond to the spacing of the coloured areas of ring 63. The ranges of rotation of casing 74 and disc 88 are limited by respective recessed portions (83, 89), Figs. 9 and 12 (not shown) of the peripheries of flange 82 and disc 88, which engage a screw 102 passing through one of a plurality of holes (104), Fig. 4 (not shown) in member 28. When the period of time it is desired to display is not within the Christian era, screw 102 is removed and inserted into a different hole 104. Rotatable dials 108, 110 indicate the present, or a selected, year.