Year: 1895

page_text: Date of Application, 25th Nov., 1895
Complete Specification Left, 25th Aug., 1896-Accepted, 3rd Oct., 1896
1. CHARLES GEORGE ARTHY, of No. 45 Fenchurch Street, in the City of
London, Merchant, do hereby declare the nature of this invention to be as
follows:-
This invention relates to a construction of locks operating in the following
manner.
The lock is composed of a number of levers, cams or equivalent devices so
arranged that one such device cannot be moved so as to release a locking bolt,
until the said device has been released by moving a second device, which in its
turn cannot be moved until released by a third device, and so on to any desired
number of devices.
Thus assuming that a locking bolt is controlled by a chain of four such devices,
say ABC D, then for unlocking the bolt, A has first to be moved to release B
this can then be moved to release C, which is then moved to release D, by the
motion of which the bolt is released so that it can turned or shot back.
The several devices are arranged to be operated either by knobs outside the
safe or other door or by inserting keys into openings for operating them, and they
are so arranged that the knobs or keyholes thereof are not situated in any regular
order corresponding to that in which they have to be operated so that it is
impossible to tell from their positions which device has to be operated first,
which second, and so on. From this it will be seen that the safety of the lock
against unauthorised opening will depend upon the number of permutations
possible with the number of controlling devices of which the lock is composed.
Thus with a series of four controlling devices as referred to above and a
fifth for operating the lock bolt, the possible permutations correspond to those
for five elements, so that the chances against unauthorised opening are very
great.
These chances are of course capable of being increased to an enormous extent
by providing either a greater number of controlling devices, or a number of
additional dummy devices, the turning of which has no effect upon the lock.
The knobs or equivalent devices by which the controlling devices are operated
are so connected to these that the former are free to turn to a certain extent
before they operate the latter, so that it is not possible to determine by trying the
several knobs consecutively which one of them is and which is not operating its
controlling device.
By preference the said devices are so arranged as to be acted upon either by
gravity or by springs, so that they tend to move back into their locking position
unless retained by hand; thus on turning A to release B, A has to be held
until B has been turned and thereby keeps A in the releasing position, and B
has in like manner to be held until C has been turned, and so on, the turning of
the locking bolt into the open position holding all the devices in the releasing
position. The bolt is held in this position by a suitable catch, so that on turning
this catch so as to release the bolt, it falls back into the locked position and thereby

page_text: allows all the controlling devices to fall back consecutively into the locking position,
the locking being thus effected automatically by the single motion of turning the
bolt catch.
The controlling devices may be constructed in a variety of ways for carrying
out the above described mode of action, thus they may either be simple lever arms
or stops, or they may be cams, wedges, or any other mechanical devices by the
movement of which they may be made to release other devices. They may also
be so arranged as to be interchangeable, so that for increased security the sequence
of their releasing action can be varied from time to time.
Dated this 25th day of November 1895.
ABEL & IMRAY,
Agents for the Applicant.
1, CHARLES GEORGE ARTHY of No. 45 Fenchurch Street, in the City of
London, Merchant, do hereby declare the nature of this invention, and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
This invention relates to a construction of locks operating in the following
manner.
The lock is composed of a number of levers, cams or equivalent devices so
arranged that one such device cannot be moved so as to release a locking bolt,
until the said device has been released by moving a second device, which in its
turn cannot be moved until released by a third device, and so on to any desired
number of devices.
•
The accompanying diagram illustrates an arrangement of lock according to this
invention presenting 9 handles to turn discs which inside the lock have lever arms
attached to them so arranged that they can be moved only in one particular order,
which is one of a very large number of possible orders or permutations. In the
diagram the discs are shewn with keyholes, into which a single key or different
keys may be inserted to act as handles. The discs D and I are dummies performing
no part of the unlocking operation, but serving only to increase the number of
ineffective permutations. The locking is supposed to be effected by the bolt h
when in its lowest position and the problem is to raise that bolt to the dotted
position so as to effect unlocking. This is done by turning G to the dotted position
freeing E, which being then turned, frees F, this being turned frees C, this when
tuined frees A, and A when turned frees H which can then be turned raising the
bolt h. The catch ¹ then engages in a notch of a freely suspended plate Q and
the bolt is thus held up in the unlocking position. On turning B so as to
raise Q, the bolt is let go; it descends effecting locking, and then all the other
aims of A, C F, E and G resume their original positions in obedience to their
weight or to springs applied where necessary.
Obviously the number and arrangement of the handles may be varied without
limit and instead of a single locking bolt there might be several of these, each
requiring for its release some particular order of operation with sets of keys or
handles.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
A lock presenting a number of handles or their equivalents which operate arms
interlocked with each other in such a manner that for the purpose of unlocking

page_text: they must be moved in one particular order, which is only one of a large number
of orders or permutations, in which the handles might be moved if they were not
interlocked substantially as and for the purpose set forth.
Dated this 25th day of August 1896.
ABEL & IMRAY,
Agents for the Applicant.