GB1429784A - Clock - Google Patents

Abstract

1429784 Geographical clocks R J HORNE 6 April 1973 [11 April 1972] 16662/72 Heading G3T A clock 10 comprises a world map delineated on a manually rotatable cylinder 16 which is mounted on a housing 11 coaxially with time indicating means driven e.g. by one or more synchronous motors 12, 13 in the housing, and a fixed indicator 18 extending parallel to the cylinder 16, whereby the cylinder and the time indicating means can be set to indicate the time at a desired longitude by registration with the indicator 18. As shown the cylinder 16 is of transparent acrylic resin and contains the time indicating means. The latter comprise transparent helical bands 30-32 scaled in hours, minutes and seconds, and a twenty-four hour scale 38 on a transparent cylinder 36 fixed to the band 30 by a pin 37. The bands are driven by respective synchronous motors or by a single motor and appropriate gearing; complete transparent cylinders may be substituted for the bands. The map has lines 41 of longitude and other lines 42 linking major cities with the lines 41 so that the time in any city can be read on the scale 38. The cylinder 36 also carries circles 39, 40 above mid-day and midnight on the scale 38.