History of Locks
More Parautoptic
Meaning: Parautoptic – Hidden from view (from the
Greek), therefore ‘More Hidden From View’.
» IT’S TEN YEARS SINCE THE
first article appeared in this
column on the Parautoptic
lock (The Locksmith Jan/
Feb 2011 Issue 12 p54/55).
The final comment in that
article promises some more
detail on the mechanics of
these fascinating locks – well
belatedly, here is a bit more…
In that first piece we
learned about Hobbs, as a
salesman for Day and Newell,
and his selling techniques.
He would demonstrate to
bankers and the like how easy
it was to compromise their
existing locks, sometimes in
seconds; this same selling
technique was applied when
he exhibited the ‘Day and
Newell Bankers Transmutable
Lock’ at the World’s Trades
Fair (The Great Exhibition) of
1851; with equally good results
having picked both the Chubb
and Bramah locks of the day.
We also learnt how the Day
and Newell lock was initially
compromised in America and
how Hobbs had improved it
whilst he was in England. The
initial weakness was in fact
to do with the curtain; Hobbs
made a simple modification
by adding a wiper. This wiper
itself was also improved
throughout the life of the lock
with later models showing
differences in design. It’s
interesting that some top of
the range locks still include a
wiper in their design today.
Original 6 lever lock to the Day and Newell
design; no wiper, no anti-pressure device.
Another area that saw
development in Hobbs version
of the lock was in the keys. The
bankers loved this lock for two
reasons; one was because the
Hobbs version was secure, the
other was due to the simplicity
in changing the combination.
The lock must have contributed
to the protocols and
procedures at institutions at the
very highest levels. Officials
could now incorporate in
addition to dual or triple control
locks a combination change at
every shift handover.
The first generation of Hobbs
Parautoptic keys were supplied
with key steps that could be
removed, scrambled and
reassembled into a different
combination. At handover, the
lock in its unlocked state, could
be locked with a completely
different key automatically
‘transmuting’ the lock into
a different combination
depending on the steps in the
new key.
Although this was a great
improvement and a convenient
process, some users found
the frequent changing of the
Hobbs Parautoptic curtain for the
7 lever lock with a flip-flop wiper
but still under spring tension.
Hobbs Parautoptic curtain for the 6 lever lock with
a spring loaded or spring tensioned wiper attached.
keys steps a little fiddly. Hobbs
now supplied a key where
the whole key bit could be
removed and another, with a
different set of steps could be
quickly snapped onto the stem.
The stems were also getting
longer as door barrier materials
caused doors to become
thicker. These detachable
heads still retained individually
removable steps though.
The final development of the
Parautoptic keys was where
the step segment was formed
as one piece and simply slid
into the bit engaging with a
small catch which firmly locked
it place, or allowed it to be
removed and exchanged with
another.
From the outset the form
or design of the bit was
especially engineered so that
one institution’s keys could not
be used in another’s locks.
The six and seven lever
Hobbs Parautoptics are also
made gun-powder proof by
inserting a brass semi-circular
plug just below the key hole
which would blow out venting
explosive gasses.
58
JUL/AUG 2020
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