GB544521A - Improvements in electric clocks - Google Patents

Abstract

544,521. Electric clocks. HAYDON, A. W. Jan. 25, 1941. No. 1010. Convention date, Jan. 25, 1940. [Class 139] In motor-driven clocks of the type in which the numerals indicating time are carried by a series of rings, the rings which are rotatable independently are supported by means which are located a considerable distance from the centre line of the row of rings in order to permit the location of the motor and the other mechanism within the rings. The rings 7 .. 10, Fig. 9, are shown supported by three rods 11 .. 13 carried by the end plates of the case and the rings comprise an "hour" ring 7 having numerals zero to twelve, a "ten minute" ring 8 having two series of numerals zero to five, a "minute" ring 9 having numerals zero to nine and if desired a "seconds" ring 10 having numerals as shown. The rings are driven by palws 25, 26, 27, Fig. 7, carried by a shaft 28 mounted on an arm 35, Fig. 2, and oscillatable by means of a cam 38 driven by the motor and so arranged that the cam rotates once per minute depressing the shaft 28 until at the end of the rotation the spring 42 causes the shaft and consequently the pawls to give their working stroke. Fig. 4 shows the "minute" ring 9 which makes one revolution in 10 minutes, being intermittently rotated or advanced by the pawl 27 engaging the internal ratchet teeth 24 of the ring 9. The pawl 27 has a cam follower 30 connected to the pawl 26 and co-operating with the cam surface 29 of the ring so that the pawl 26 only engages the ratchet teeth of the "ten minute" ring 8 when the follower 30 enters the part 28J of the cam surface 29, i.e., in one part of the revolution of the minute ring. Similarly a cam follower 32 engages a cam surface on the "ten minute" ring 8 and is connected to the pawl 25 which engages the ratchet teeth of the "hour" ring 7 when the follower 32 enters the depression in the cam surface of the "ten minute" ring. The "seconds" ring 10 is continuously rotated by gear 40, 45, 44, 43, Fig. 2, from the motor. The numerals on the rings are readable through a transparent pane 47 of the window 6 in the clock casing. Specifications 392,405 and 426,242, [both in Group XXXV] are referred to.