Patent GB-724278-A (GB)
Title: Time announcing system
IPC: H04M3/50
Filed: 1951-12-18
Abstract: 724,278. Automatic exchange systems. AUTOMATIC ELECTRIC LABORATORIES, Inc. Dec. 18, 1951 [Feb. 13, 1951], No. 29635/51. Class 40 (4). [Also in Group XXXVIII] In apparatus for making periodic announcements at predetermined times of the type described in Specification 675,124, D.C. is supplied to the capstan motor 212<1> driving the magnetic sound tape 210<1> (see Group XXXVIII) to stop it instantly after each announcement. In operation, a pushbutton 293<1> is pressed to operate relays 155, 145. The relay 155 operates holding circuits for itself and relay 145, disconnects the trunkbusy circuit from earth and prepares an alarm circuit for indicating breakage of the tape. The relay 145 causes the reel motors 213, 214 to be energized. Cams 107<1>, 110<1> are driven by a synchronous motor 100<1> to rotate once every six hours, cam 111<1> every hour, cam 112<1> every minute and cams 113<1>, 114<1> every fifteen seconds. When the minute cam 112<1> closes contacts 1231 relay 180<1> operates and holds over its lower winding.: While the sixhour cam 107<1> closes the contact 118<1>, the relays 150<1> and 130 are not operated and the reproducing head 207 is therefore connected to the amplifier. The cam 113<1> then closes contacts 124<1> to cause a relay 280<1> to operate the relay 160 which closes a circuit to the capstan motor 212<1>. The tape is then driven and a time announcement is picked up by a magnetic reproducing head 207. A head 211<1> then picks up the control signal which operates a relay 296<1> and the lower winding of the relay 280<1> to cause the braking D.C. to be supplied to the capstan motor 212<1>. The cam 1141 then closes contacts 125<1> to cause the tone signal from the oscillator 191<1> to be placed on the trunk line. The relays are then restored and operated again to give the next time announcement followed by the tone signal. After six hours, relay 150<1> is operated by cam 107<1> to reverse the leads to the capstan motor and thus cause the tape to be driven in the reverse direction, and to disconnect the head 207 and connect a head 208 to the amplifier. During the 8 seconds pause between the time announcements commercial announcements may be made. The commercial announcements are recorded in parallel tracks on a film 187<1>, Fig. 2, mounted on a drum rotated by a motor 195<1>. A cam 108, Fig. 1, operates a relay 165, Fig. 2, to supply current to a motor 230. The motor 230 drives cams 231 to 237 and moves the reproducing head 188<1> across the tracks. When the head is associated with the first sound track, the cam 231 operates the relay 165 to supply D.C. to the motor 230, to stop it and hold the head over the sound track. A cam 109, Fig. 1, operates a relay 198<1>, Fig. 2, to supply A.C. to the motor 195<1> and drive the drum. The announcement is then delivered over the trunk line. An abutment 186 on the drum then restores relay 198<1> to supply D.C. to the motor 195<1> and stop the drum. After the next time announcement, the cam 231 again operates the relay 165 to cause the next commercial announcement to be delivered to the trunk line. If only commercial announcements are desired, switch contacts 169 are opened and left open and contacts 163 are closed to operate relay 165 and motor 230 to shift the head. Since contacts 169 are open the relay 165 does not operate to shift the head. If a programme clock is to be used to control the sequence of commercial announcements, contacts 169 are opened and cams 232 to 237 corresponding to each of the sound tracks are used. If desired the commercial announcements may be entirely disconnected. To show that the machine is running in proper sequence an alarm circuit is provided to indicate if the motor 212 is running when it should be at rest or vice versa.