US1696261A - Transmission system - Google Patents

Description

Dec. 25, 1928. 1,696,261

5. H. WILLIAMS TRANSMISSION SYSTEM Filed Aug. 9, 1927 /A/ vzw 70R JA /a 15. W/LL/AMJ I DRIVE) Patented Dec. 25, 1928.

UNITED STATES PATENT OFFICE.

SAMUEL B. WILLIAMS, OF BROOKLYN, NEW YORK, ASSIGNOR TO BELL TELEPHONE LABORATORIES, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TRANSMISSION SYSTEM.

Application filed August 9, 1927. Serial No. 211,678.

This invention relates to transmission systems and its object is to improve systems for the distribution of programs to subscribers over physical lines.

-A feature of the invention is a program distribution system in which a subscribers combined program indicating dial and switch operating impulse transmitter is arranged to rotate in a single direction to operate a switch at central ofilce to select successive programs and also to act once during each complete cycle to restore the central ofiice apparatus to normal.

In the drawing Fig. 1 illustrates a system including a subscribers line, and a portion of the central oilice equipment.

Fig. 2 shows the details of the impulse transmitter and program indicator located at the subscribers station.

By means of a specially constructed controlling dial, the subscriber to a broadcast service is enabled to select any deslred one of a number of programs and to receive such program on a receiving set at his premises. The subscribers controlling 1nstrument is arranged to transmit such operating impulses by rotating the control handle in a forward direction. This instrument also has a dial which serves as an index to the particular program to which he is listening.

The construction of the combined impulse transmitter and'indicator dial is shown in detail in Fig. 2. A control handle 21 is attached to the shaft 25 to which is secured a ratchet wheel 26. A spring pressed pawi 27 cooperates with the ratchet 26 to prevent the control handle 21 from being turned in the reverse direction. A pointer 22, secured to the handle 21, moves over a dial 2G. The dial 20 has numerals or other designations to indicate the different programs avaiiable.

The shaft 25 carries a yielding roller which moves over the serrated men'iher 23 to hold the shaft 25 fir in any position to also carries an arm 2e, one end which is secured a coil spring of the s ring is fined to a secon The two shafts are held in nor: to each other hy means at pins and 31.

The 35 carries an impuls wheel 4&3 which has a numhe .eth so ondir to each position oi between the springs 32 and 33 and also a closure between the springs 33 and 34. Normally the springs 33 and 34.- remain open.

In Fig. l is shown the subscribers receiver 1, and an amplifier 2. This set is connected through a repeating coil 3, to the line leading to the central office, and there terminating in a switch having the brushes 12, 13, and 14:. The central ofiice switch has access to a number of difierent program equipments 16, 17 and 18.

The operation of the system will now be explained. Assume the subscriber wishes to listen to the program being sent from the equipment 18. Knowing the name or number onhis dial corresponding to this program, he seizes the handle 21 and rotates it until the pointer 22 reaches the proper position. During the rotation of the handle 21, the spring 29 is tightened, which immediately causes the shaft 35 to rotate in the same direction to bring the pin 31 back into engagement with the'stop pin 30. During rotation, the impulse springs 32 and 33 close and open a corresponding number of times/ On the first closure of the impulse springs, a circuit is completed from batter through the winding of relay 9, lower le t winding of coil 8, thence over the. lower side of the line, through the lower right winding of coil 3, springs 32 and 33, to the upper right winding of coil 3 thence over the upper side or? the line, the upper left winding of coil. and the winding of relay 10 to ground. With relays 9 and 13 operated, a circuit is closed from grourid through the front contacts of these clays, windings of siow rele 3e relay 11, ding of the stepping Y t 15, to but ery. On the next opening i aanet 15, which in s the hrushes l2,

M is or seen suc- 1e line, relay 9 releases and if oeeding impulse the brushes of the switch are advanced until finally they stand on the set of terminals corr onding to the program distributing equlpment. 18. During the sending of the impulses, rela 11 remains operated, but after the impu es have been transmitted and an interval elapses,

this relay releases to complete a circuit trom the program set 18, through the brushes 12 and 13 and the contacts of said relay to the ri%lethwindings of coil 8.

en the shaft 35 first starts to rotate, the governor weights 36 and 37 raise the disc 38 to permit the spring 40 to move into engagement with the spring 41. The sprin 40 and 41 serve to short-circuit the receivmg set 12, during the sendin of impulses. After the impulses have been sent and the shaft 35 comes to rest, springs 40 and 41 are again opened to render the receiving set efiective. The program is now received at the subscribers station and he ma listen to. it until it is completed or until e desires to listen in on some other program or to disconnect his line entirely from the central ofiice equipment. To listen in on another 1pro am he merely continues to rotate the an le 21 until the pointer 22 reaches the desired program.

In order to insure that the switch at the central ofiice is in, chronism with the substation dial, the ial is so arranged that once per revolution it causes the switch to restore to normal. As the control handle 21 is turned from the last program position toward the first program position, the cam 43 presses the spring32 against the spring 33 and the latter spring against the spring 34. The closure between these springs results in applying ound potential to both sides of the hne. This causes the operation of relay 9 and the release of relay 10. With this condition, a circuit is closed through the contact of relay 9, back contact of relay 10, brush 14, and its associated terminals, contact of magnet 15, winding of relay 11, winding of magnet 15, to battery. The magnet 15 interrupts its own circuit and steps the brushes 12, 13, and 14 bacl: to normal position. The closure b the cam 43 is sufiicientl lon to permit to restore. A r t e cam 43 has passed under the spring 32, the spring drops into a notch openin the contacts. This notch may represent t 'e normal position in which no 1plrograin is selected.

e room set at the subscribers sta-- tion has been shown in dia atic man ner but it is to be'understo that it may be of any suitable What is claims is:

1. In combination, a central oflice havan automatic switch therein arranged to take a plurality of successive settin without releasing, circuits selectable by said e switch 'ments selectable b switch, a subscribers line leading to said switch, a transmitter atthe substation adjustable to any of a plurality of positions to send a correspon ing number of 1mpulses over the line, means responsive to said impulses to set said switch to select a desired circuit, a dial on the transmitter indicating the circuit selected, and means controlled by the transmitter once during a complete operation for restoring the automatic switc 2. In combination, a central oflice having an automatic switch therein, circuits selectable by said switch, a subscribers line leading to said switch, a transmitter at the substation adjustable to any of a plurality of positions to send a corresponding number of impulses over the line, means for retaining the transmitter in its adjusted position; means responsive to said impulses to operate the switch to select one of said circuits, indicating means adjustable with the transmitter to indicate the circuit selected, and means controlled by the transmitter during each complete cycle of operation to restore said automatic switch.

3. In combinatioma central ofiice having an automatic switch therein arranged to take a plurality of successive settings without releasing, a plurali of program sending equipments selectab e by said switch, a subscribers line leading to said switch, a transmitter at the'substation adjustable to any of a plurality of positions to send a corresponding number of impulses over the line, means responsive to. said impulses to set said switch to select a desired program, a receiving set at the substation for receiving the selected program, an indicat' device adjustable with the transmitter to indicate the pro am being received, and means controlled y the transmitter for restoring said automatic switch.

4. In combination, a central ofiice having an automatic switch therein rogram distributing uipments selected by said automatic switc a subscribers line extending to said switch, a transmitter at the substation movable to any of a plurality of positions to send impulses over the line, said transmitter remaining in the position last used until moved to a new'position, means responsiveto said impulses to operate said switch to select a desired program, a dial on the transmitter indicating1 the program selected, and means contro ed by the transmitter during each cycle of operation for restoring the automatic switch to normal.

5. In combination, a central office having an automatic switch therein, program equi said switch, a subscrib ers line, a transmitter at the substation rotatable in one direction only to successive positlons to send over the line a number of impulses corresponding to the amount of rotation, means responsive to the impulses for setting said switch to select a desired equipment, an indicating device on said transmitter for designating the program selected, and means controlled by the transmitter while moving from its last to its first position to restore said automatic switch to normal. v

6. In combination, a central oflice having an automatic switch therein, circuits selectable by said switch, a transmitter at the substation adjustable to different successive positions, a pair of impulse springs actuated by the transmitter during each adjustment to send a corresponding number of impulses over the line, means responsive, to said impulses to actuate said switch to select a desired circuit, a dial on saidtransmitter indicating the circuit selected, and a second set of contacts closed by the transmitter for restoring said automatic switch to normal.

7 In combination, a central ofiice having an automatic stepping switch therein arranged to advance from one selective position to another, circuits selectable by said switch, a subscribers line leading to said switch, a transmitter at the substation adjustable to a plurality of positions to send a corresponding number of impulses over the line, means responsive to said impulses to set said switch to select a desired circuit, a dial on the transmitter indicating the circuit selected,

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