Patent GB-636136-A (GB)
Title: Improvements in electric time recording or time signalling apparatus
IPC: G04C13/02
Filed: 1947-06-19
Abstract: 636,136. Electric clocks. MASSON, E. P. June, 19, 1947, No. 16226. Convention date, June 28, 1946. [Class 139] [Also in Group XIX] Electrical time recording or signalling apparatus comprises a number of slave chronometric members adapted to be controlled by a master chronometric member, wherein each slave member appertains to a given unit of time and suffers a given displacement for each of such units and carries a plurality of electrical contact elements, each of which represents one unit of time, said elements being arranged in consecutive series increasing by one unit in the direction of displacement of the chronometric member, and wherein a movable member carrying electric contacts is displaced in such a manner as to come periodically into contact with the contact elements of the respective slave chronometric members and to sweep in succession over the individual contact elements of each series as the said members are themselves displaced to present their series of contact elements to the line of motion of the said movable member, such contact between the movable member and the said contact elements controlling a supply circuit fordevices adapted to record a time signal for each of the contacts encountered by the movable member. As shown in Fig. 1 the slave chronometric members comprise four cylinders S, DS, M and DM corresponding to seconds, tens of seconds, minutes and tens of minutes respectively. Each cylinder surface is divided into the appropriate number of strips, each of which carries a corresponding series of electrical contact elements. A pendulum 1 closes contacts 2 every second to energise an electro-magnet 5 which through a pawl and ratchet 6 " steps-on " the unit seconds cylinder S through a tenth of a revolution. When the cylinder S passes from 9-0 a cam 7 closes contacts 8 to energise an electro-magnet 9 which through a pawl and ratchet 10 " steps-on " the tens of seconds cylinder DS through a sixth of a revolution. The cylinders M and DM are " stepped-on "' in similar fashion through electro-magnets 13 and 17 and cams 11 and 15. Each alternate second an arm 24 carried by a vertical spindle 19 is moved either by a return spring 28 or, upon energisation of an electro-magnet 30, by a spring 29 so that brushes 25, 26 carried thereby scan the uppermost strips of the cylinders DM and M and DS and S respectively. As the brushes 25, 26 meet the contacts on the strips impulses are sent to a recording device 33, 33a which produces a record, such as is shown in Fig. 4, indicative of time. To avoid any sparking between the brushes 25, 26 and the contacts there may be employed an arrangement, Fig. 3, not shown, in which the brushes control the contacts of the grid of a triode valve, which supplies the recording device 33, 33a when its grid is placed at zero potential. A second triode valve supplies the electro-magnets 5, 9, 13 and 17 and a third triode valve supplies the electromagnet 30. The grid of the second triode valve may be placed at zero potential to interrupt the supply to electro-magnets 5, 9, 13 and 17 to permit setting of the cylinders by the operation of independent push buttons.