The Newmanry History

54C Page 355

A bedstead is a system of pulleys round which the tape is driven by a

There are four bedsteads A,B,C,D: to ensure simultaneous scanning of

To reduce the tearing of sprocket-holes, two of the pulleys are driven at

The tapes are draped loosely on the pulleys, centrifugal action tends to

Between the "Gate" and the sprocket wheel the tape moves past two engraved

The tapes, which are of course continuous loops, are jointed flexibly with

One spring switch is used both for starting and stopping: it is thrown down

Each bedstead has 13 photo-electric cells which scan the tape as it passes

One of the photo-cells scans the sprocket-holes, permitting the counters to

In each position of the tape 10 of these cells scan the 10 dots and crosses

The remaining two photo-cells look for the start and stop signs which are

A start sign causes the machine to start counting.

A stop sign causes the machine to stop counting, transfer the count to

Only one start sign and one stop sign are used as such at any time; these

The start signs are used also for finding the relative positions

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