CLOCK No. 15

D 1252
Issue 1, 27/10/38

“Clock No. 15”

1. Description
Clock No. 15 is a portable tell-tale clock which has been provided in large P.O. buildings for checking the times at which the night patrol reaches certain points in the course of his rounds.  At these positions a numbered registering key is fastened to the wall, etc., by a chain.  This key, when inserted in the portable recording clock carried by the patrol, causes the number of the point and the time to be recorded on a paper roll or disk inside the clock.  There are three types of tell-tale clock in use, one of which, with the key, is illustrated.

2. Supersession
The clock is now obsolescent and will not be installed in future buildings.  It has been superseded by an electrical system (see D 1251).

"Universal" type is shown pictured to the right

There were three types of tell-tale clocks, in use, viz., the "Universal," the "Newman" and the "Dent."

The "Universal" clock is enclosed in an aluminium dust-proof case fitted with a lock and key and will work for 50 hours with one winding.  The dial has a single hand indicating the minutes; the hours are shown through an aperture in the dial by a revolving disc. Black figures on white ground represent the hours from 6 a.m. to 6 p.m. and white figures' on black ground the hours from 6 p.m. to 6 a.m.  An unlimited number of stations may be registered, a fresh numbered key being squired for every additional station.  The record is continuous and is made upon a roll of paper slip contained within the clock.  The revolution of the key in the operation of registering, presses the tape against a type wheel (not shown) and moves the tape forward one space ready for the succeeding impression. Once inserted and partially turned, a key cannot be with­drawn without completing the registration.

The type wheel is connected with the clock and prints the time upon the tape, while the key marks its own number thereon.  The used tape may be withdrawn at any time by unlocking the clock and no replacement is necessary until the whole roll of tape has been used up.

"Dent" type

"Newman" type

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Last revised: July 25, 2022