Mechanism No. 16 | ||||||||||||||||||||||
| Mechanism No. 16 is used in the
Box, Coin
Collecting No. 16 that would be fitted in public call offices and subscribers' coin-box installations in C.B.S. and
Magneto exchange
areas. The Mechanism No. 16 is connected to the Box, Coin Collecting No. 16 with a 12" piece of IRV PVC three wire cable. The Box, Coin, Collecting No's 16 and 16A just had a terminal block fitted to the rear panel of the case. The Box, Coin, Collecting No. 16B and 16C used a Bellset fitted inside the casing, instead of the terminal block and external bellset. The Mechanism No. 16 had no A&B buttons fitted as the calls where under the control of the operator. Coins were inserted under the instruction of the operator. The switch wiring on the mechanism has no diagram but can be clearly identified in circuit diagram N2403. The Transmitter No. 21 was later replaced by the Transmitter No. 25. The original mechanism accepted Pennies, Sixpences and Shillings. The Mark 3 variant is decimalised and fitted with 2p and 10p coin slots. Diagram - N1184. Drawing - 63907 (Mark 3 Mechanism). Drawing - 75262 (Coin Chutes). Specification - S261 (Mark 3).
Operation
The following circuit diagrams and the
picture shown above should be
referred to in conjunction with the operating instructions below:-
The coin mechanism is a post payment type. The user just picks up the telephone (and cranks the generator if it is on a Magneto exchange) and waits for the operator to answer. On answer the operator connects the caller to the required number and instructs them as to what money to insert. There are no A or B buttons and no refund provision, but rejected coins are returned to the user. The operator totally controls the call and can also request additional payment mid call.
COIN
SLOTS
Three coin slots marked Penny, Sixpence and Shilling respectively are provided on the top of the box. The size of each slot is such to prevent the use of coins of a larger size than that of the denomination shown, or badly bent or misshapen coins. COIN GUIDES Each coin inserted rolls down an inclined coin guide associated with the respective coin slot. In doing so the coin is tilted and caused to pass over a suitable coin gauge. COIN GAUGES If a smaller coin than that indicated has been inserted, it is thrown out by means of the coin gauge and falls into the Refund shute to be returned to the caller. CRANK ARM AND SPRING ASSEMBLY
BELL GONGS
At the end of the coin guides is fixed the gong assembly. Each coin, after passing its respective coin gauge, continues to roll down the coin shute and is therefore caused to strike either the wire or bell gong in the following manner. A penny strikes the wire gong once; a sixpence strikes the bottom edge of the bell once; a shilling strikes the bell gong twice, i.e. by means of a double coin guide a shilling is caused to strike both the tap and bottom edges of he bell gong. After striking their respective gongs the coins fall into the cash box. COIN BOX TRANSMITTER The coin box transmitter is fixed inside the bell gong, the combined item being know as the Transmitter No. 21 or Transmitter No. 25 (later type). The coin box transmitter is practically unresponsive to speech but responds to the mechanical vibrations of the gongs. The transmitter injects the gong or wire sounds onto the line, so the operator can hear them. ESCAPEMENT MECHANISM The escapement mechanism is interposed between the coin slot crank arm and spring assembly. It is a pendulum device that delays, by approximately 3 seconds, the return to normal of the spring assembly thus ensuring the coin box transmitter being in circuit to transmit the gong signals to the exchange operator. The spring assembly, once restored to normal, short circuits the Transmitter No. 21 of 25 to prevent ambient noise affecting the quality of the call and reconnects the telephone transmitter back into circuit. COIN CHUTE EXTENSION |
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Last revised: October 01, 2025FM |
