Patent GB-426559-A (GB)
Title: Electrical actuating means for a time indicator
IPC: G04C13/10
Filed: 1933-10-02
Abstract: 426,559. Electric clocks. SIEMENS BROS. & CO., Ltd., Caxton House, Tothill Street, BROOME, J. H., 80, Leyland Road, Lee, and SOUTHAM, A. A., 58, Larchwood Road, New Eltham, all in London. Oct. 2, 1933, No. 27071. [Class 139] In a time indicator comprising a number of sets of numeral bearing slats carried by endless chains or bands, there being a set of slats for each time indicating element, for example, minutes (units), minutes (tens), hours (units), hours (tens), and A.M.-P.M. to be displayed, the units (minutes) indicator element is advanced by timed impulses received, for example, from a master clock, and the other indicating elements are advanced therefrom through transfer mechanism under the control of stepping switches. In the embodiments shown forward and/or, reverse drive stepping switches are associated with the various time indicating elements, and a striking mechanism is described. The indicator may be of the type described in Specification 357,616, in which each set of slats is carried by endless chains and is driven by a constantly rotating shaft when a clutch magnet is energized, the clutch being automatically disengaged to stop the indicator element when it reaches the next display position. The driven side of the clutch, which makes one revolution between indications, has cams C1, C2, Fig. 2, which operate contacts c1, c2 designated muc1, mtc1, ... , muc2, mtc2, ... , &c. in the other Figures according to the clutch magnet MUMC, MTMC, ... associated therewith. In the embodiment shown in Fig. 1 impulses from a master clock energize a relay X every minute. Each impulse causes energization of the minutes clutch magnet MUMC over contacts tp2, tpa1, to advance the minutes units display by one, during which operation a drive magnet MUDM is energized, over cam contacts muc1, to step a forward drive minutes units switch MU1. When a tenth minute is being registered, a transfer relay MUT is energized over the wiper MU1, in parallel with MUMC, and, at contacts mut2, energizes the clutch magnet MTMC to advance the minutes tens display and the minutes ten switch MT1, one step in a similar manner. When the sixtieth impulse is received, a transfer relay MTT is energized over wiper MT1 in parallel with clutch magnet MTMC and effects stepping of the hours units indicator through clutch magnet HUMC, and the hours units switch HU1, HU2. Similarly, at the tenth hour a transfer relay HUT, operated over HU1, energizes the hours tens clutch magnet HTMC to advance the corresponding display and the hours tens switch HT1, HT2. Each time indicating element has eleven slats. The slats of the minutes unit set are marked blank, 0, 1 ... 9 respectively, and since, when the blank face is displayed wiper MU1 rests on its first contacts to which + ve is connected, the clutch magnet MUMC is always energized immediately to advance the display from blank to 0. The minutes tens slats are marked blank, 0 ... 5, followed by four blanks, and the indicator element is immediately stepped through these blank positions due to +ve connected to the corresponding contacts of bank MT1. The hours tens slats are marked blank and 1 alternately, with a blank for the eleventh face. The hours units slats are marked blank, 0 ... 9, respectively, and, when the hours tens display is blank, are advanced from 9 through the blank position to display 0 as for the minutes units indicator. When the display is 11À59 and the next impulse is received the display is changed to 12À00 and a relay HTT is energized over wipers HT1, HU2 to energize clutch magnet DMC to change the display of the A.M.-P.M. indicator element from A.M. to P.M. and step a switch D1. A.M. and P.M. are marked on alternate slats, the eleventh slat, however, being left blank and the indicator stepped immediately through this position. When 12À59 is displayed and the next minute impulse received, all the lining up switches MU1, MT1, HU1, HT1 are advanced to change the display to 1À00 P.M. If the hours are to be indicated as from 0 to 23 the connections to the banks HU2, HT2 are modified as shown in the enclosed rectangle, Fig. 1, the hours tens slats are marked blank, 1, 2 repeated, the tenth and eleventh slats being blanks, and the A.M.-P.M. indicator element dispensed with. Key contacts k are provided whereby the clutch magnets may be energized and the display set manually. The control arrangements may, alternatively, provide for zero displays instead of blanks in the hours tens. In another embodiment the minute pulses energize a relay TP, Fig. 3, and are registered on a 52 point reverse drive stepping switch M1, M2, ... M4. Only 30 contacts of the 52 are used, a self-interrupting circuit being made to the drive magnet MDM to step the switch over the " spare " contacts, shown commoned in the banks M1. Each revolution of switch M1, ... therefore corresponds to 30 minutes. At each sixtieth registration a transfer circuit is made over contact rc1 to energize the drive magnet HDM of the hours registering switch H1, H2, ... H4, the contacts rc1, rc2 being changed over by a cam or like mechanical device at each revolution of switch M1, .... Associated with the minutes switch M1, ... are minutes switches MU1 (units) and MT1 (tens) which are adapted to line up with the wipers M2, and M3, M4, respectively, and in so doing interact with the clutch magnets MUMC, MTMC to set the corresponding indicator elements to display the minutes registered on switch M1, .... Hours units HU1, hours tens HT1, and the A.M...P.M. switch D1 are adapted to line up with wipers H2, H3, H4 of the hours switch and control the clutch magnets HUMC, HTMC and DMC to set the corresponding indicator elements. In another embodiment use is made of eleven point forward drive switches, each of which, however, has three staggered wipers forming in effect thirty-three point switches. The operation is somewhat similar to that shown in Fig. 1, except that each indicator element has twelve slats and the hours are indicated 1 ... 12 on one set of slats. Striking mechanism. The striking is effected on a gong EB, Fig. 4, connected to the bank CH2 of a stepping switch CH1, CH2, CH3, the contacts 2, 6, 10, ... in the bank CH1 being connected seriatim to the twelve contacts representing 1, 2, ... 12 hours in bank H1, Fig. 3. At alternate half-hours, contacts rc2, Figs. 3, 4, change over from the position shown, and the gong EB, which strikes once on energization, is operated over contacts rc2 and ce1 of the slow-to-release relay CE. At each hour a relay CA is energized over contacts rc1, Fig. 3, and locks over contacts ca1, cd1, whereupon circuits are made for slow pulsing relays CB, CC which interact slowly to step the switch CH1, ... , the gong being actuated over contacts ca5, cd3, cb2 at every fourth contact, 1, 5, 9, ... of wiper CH2. The switch is advanced until wiper CH1 encounters the contact marked by the wiper H1 of the hours switch, Fig. 3, when, the required number of strokes having been made, a relay CD is temporarily energized. Relay CA thereupon releases, breaks the gong circuit at contacts ca5 and at ca2 provides a homing circuit for the stepping switch CH1, .... Alternatively, the wiper CH1 of the switch CH1, ... , may normally rest on the contact corresponding to the current hour and effect striking during its slow stepping from this position to home position, after which it may be rapidly stepped to the new " hour " position.