Patent GB-1308509-A (GB)
Title: Digitally indicating clocktimer
IPC: G04C17/00
Filed: 1970-07-29
Abstract: 1308509 Clocks GENERAL TIME CORP 29 July 1970 [6 Oct 1969] 36789/70 Heading G3T [Also in Division H3] A digitally indicating clock has apertures 51, 52, 53 in the front panel 44 displaying, respectively, minutes, tens-of-minutes, and hours. A further aperture 54 displays "seconds" and an aperture 56 shows the pre-set time in hours for the sounding of an alarm buzzer and the switching on of a radio 80, this time being set by a wheel 57. A selector lever 60 is movable into four positions, "on", "off", "auto" and "alarm". The "on", "off" positions permit direct switching on and off of the radio, the "auto" position causes the radio to be switched on at the pre-set time and the "alarm" position causes the radio to be switched on at the pre-set time followed a few minutes later by the buzzer. To obtain additional sleep after sounding of the buzzer a drowse button 75 is pressed to cancel the alarm for about ten minutes after which the buzzer sounds again. The button 75 may be pressed any number of further times to obtain additional sleep periods. A sleep lever 70 movable over a scale calibrated 0-60 minutes permits the user to fall asleep with radio music, the radio switching off after the interval set by the lever. The clock mechanism, Fig.4, comprises an A. C, synchronous motor 100 provided with a buzzer blade B. Fig.2, the output pinion 101 meshing with a gear 102 coupled by a shaft 103 to the seconds drum 104. A pinion 105 in the seconds drum serves as the input element to a five-station Geneva wheel 106 connected through a friction drive, Figs. 8, 9 (not shown) to a minutes drum 110, this drive including an output gear 111 and integral setting gear 112 the gear  112 meshing with a time setting wheel 55 projecting through the panel 44. The drum 110 drives the tens-of-minutes drum 120 through a pin 114 driving a six-station Geneva wheel 115, the wheel 115 having three pins 116 driving a four-station Geneva wheel 117. The drum 120 drives the hour drum 130 through two pins 121 driving a six-station Geneva wheel 122, two pins 123 on the wheel driving a four-station Geneva wheel 124. The drums 110, 120, 130 have sprockets 148, 158, 168 driving, respectively, endless loops of tape 140, 150, 160 on which are printed  indicia for indicating the time, these tapes being shown in developed form in Fig.2a. Each tape has a length equal to the periphery of its associated drum multiplied by a low whole  number, thus, tape 140 has a length equal to twice the periphery of the drum 110. The tape lengths and the reduction ratio of the Geneva drives are so related that for each revolution of drum 110, drum 120 rotates # rev. and for each revolution of drum 120, drum 130 rotates 1/6 rev. Each tape, e.g. tape 140, passes over two idler rollers 144, 145 and a translucent guide member 141 arranged behind the panel 44. Lamps 171 are mounted behind the member 141 and the tapes are of flexible plastic with translucent numerals on an opaque background.  The drive train for switching on the radio and buzzer at the pre-set time is driven from the output gear 111 and comprises gears 181-185 driving a shaft 186, a pinion 187 on the shaft driving an hour wheel 189 on a twelve hour cycle. To produce endwise movement of the wheel 189 at the pre-set time, an alarm set drum 190 carrying numerals 1-12 has cam surfaces 191 co-operating with cam follower surfaces 192 on the hour wheel. To this end the hour wheel 189 is mounted on a shaft which is axially slidable and biased by a leafspring in a direction to keep the cams in engagement, Fig.15 (not shown). The alarm set wheel 57 is directly connected to the drum 190. The operation of the selector lever 60 and drowse button 75 is described with reference to Figs.17- 32 of which only Fig.17 is shown. Briefly, lateral movement of the hour wheel 189 releases a trip lever 210 mounted on a shaft 211 and biased by a spring 214 so that when the lever is released a pin 235 on the lever is arrested by the selector lever 60. Rotary movement of the shaft 211 to a degree determined by the position of lever 60 causes rotation of a shaft 216 through gear racks 213, 215. A cam 217 on the shaft 216 controls a switch 220 comprising lower and upper blades 221, 222 for switching on and off the radio. The buzzer blade B is normally held raised in its inactive position by an arm 252 of the lever 250 having a cam follower arm 251 engaging the cam 217. However, lowering of the arm 252 occurs at the pre-set time when the lever 60 is in the "alarm" position.