GB439035A - Improvements in or relating to clocks - Google Patents

Abstract

439,035. Clocks, meters, and counting- mechanism. ENGELKE, W., Red Roofs, Blenheim Road, St. Albans, Hertfordshire. April 28, 1934, No. 12887. [Class 139] [See also Group XIX] A clock, meter, or counting-mechanism has a transmission comprising two or more ratchet wheels mounted upon nested sleeves, a cam or eccentric fast with one ratchet wheel, and a pawl-carrying arm which is actuated by the cam or eccentric to cause the pawl to advance the next ratchet wheel, there being a hand on each sleeve which moves over a dial common to all the hands. The mains-supplied synchronous motor 1 drives a spindle 2 at 120 revolutions per minute. Freely mounted on shaft 2 and nested on one another are three sleeves s, m, h having rigid with them the seconds, minutes, and hour hands s<1>, m<1>, k<1> and also three ratchet wheels s<2>, m<2>, h<2> respectively. An eccentric 9 rigid on shaft 2 rotates in a slot 8 in an arm 7, pivoted at 6 to the back plate 5 and having at its free end a pawl 12 which drives the 120-tooth seconds ratchet s<2>. Rigid with ratchet s<2> is a singledrop cam 15 which operates lever 17 and pawl 19 against spring 21 so that the pawl drives the 60-tooth minute ratchet m<2>. Rigid with m<2> is a five-drop cam which similarly drives the 60-tooth hour ratchet. Instead of the pawls driving intermittently, as in Fig. 3, the arrangement of Fig. 5 may be used, wherein the cam 15 steadily raises lever 17 and pawl 52 steadily drives ratchet m<2> until, when point 16 drops off the cam 15, the pawl 52 takes over another tooth.