An Improved Lock.
Year: 1893

page_text: Date of Application, 5th July, 1893-Accepted, 2nd Sept., 1893
COMPLETE SPECIFICATION.
An Improved Lock.
I, JOHN BOULDERSON of 10, Ashburton Road, Southsea, in the County of Hants,
Lieutenant-Colonel Retired of Her Majesty's Army, 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:-
My invention relates to an improved lock, and has for its object to provide a
simple and easily operated form of combination mechanism whereby the operation
of the bolt either directly by hand or under the operation of a key is so controlled
that the retraction of the bolt is only possible by first setting the elements of the
combination in a prearranged position relatively to each other and to the bolt.
The combination is constituted by a series of flanged rings so mounted as to be
independently revolvable about a common centre, the operative flanges being
in different planes superposed the one above the other and presented in the path of
a lug upon the bolt which is mounted to slide in a direction normal to the rings
whose flanges are radially notched to give passage to the bolt when the notches of
all the rings are brought into line with the lug on the bolt. To facilitate the
operation of setting the rings their hub portions are fitted concentrically within
one another and extend to a common plane flush with the face of the lock, the faces
of all the rings being provided with circles of letters, so that by setting or
adjusting the rings in such manner that the combination of letters when read
diametrically across the series or in any other arbitrary manner form a predeter-
mined key word the notches in the rings will be set in proper position to give
passage to the lug on the bolt and allow the lock to be opened. The key word
being known only to those entitled to use the lock it is evident that if the combina-
tion be formed of a sufficient number of rings, the opening of the lock without a
knowledge of the key word to which it is set is practically impossible.
Reference is to be had to the accompanying drawings, forming part of this
Specification, wherein Figure 1 is a face view of the lock, the casing being in
section on line 1-1 Figure 2 which figure is a horizontal section. Figures 3 and 4
are detail perspective views.
A are the revolvable rings constituting the combination by which the retraction
of the bolt B is controlled. Each ring A is mounted to revolve freely and
independently of the others, and for this reason each is seated about a stationary
ring C, the rings C being of L-section and supported by their flanges being
notched (see Figure 4) so as to engage in corresponding notches d in the sides of
the fixed pillars D (see Figure 3) whereby the rings are both supported in position
and prevented from turning, so as to avoid the communication of rotary motion
from one ring A to another. The rings A. are also of L-section, the bosses of both
sets of rings being of different diameters, so as to fit inside one another in alternate
order, as shewn, a ring C intervening between each two rings A. The outermost
ring A is held in place by inwardly projecting lugs d' on the pillars engaging in a
circumferential groove in the ring or by an inwardly turned flange on a circular
case enclosing the whole of the rings but not shown in the drawings. The boss of
each ring A is provided with a knob or other handle for turning it by and has
engraved upon its end face a circle of letters to guide the operator in setting it and
baffle any attempt to tamper with the lock. The flanges of all the rings A are of
uniform diameter so that when presented in the path of a lug b on the bolt, the
latter if forced back will press equally against all the rings so that it is impossible
by applying pressure to the bolt and turning the rings separately, to ascertain
when the rings are in the proper position for unlocking. The bolt B is fitted to
slide in a direction normal to the rings A and can only be thrown back to the

page_text: unlocked position when the rings A are so set as to offer no obstruction to its
motion. For this purpose the flange of each ring A has a radial notch e of a width
to just give passage to the lug band of a depth corresponding to the throw of the
bolt so that when all the notches e are brought into line with the lug b, as
represented in Figures 1 and 2, the bolt which is shewn in the locked position, can
enter them freely and be thrown back to the unlocked position. The flanges of the
rings C have radial notches c with which the notches e coincide when in position for
'permitting the unlocking of the bolt B.
The bolt B is shewn as directly operated by a knob handle, but it will be
obvious that it may be thrown by a key in the manner of an ordinary lock. The
alphabetical combination rings are shewn as fitted in the thickness of the door from
the rear or inner face thereof, but it will be understood that the lock may be fitted
in various ways, and my invention is in no wise limited in this respect. Being of
very simple construction these combination rings may be applied to many locks,
such as those of doors of cupboards, apartments, and articles of furniture for which
the protection afforded by ordinary locks is inadequate.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The herein described combination of concentric, superposed, and independently
revolvable letter rings with alternate stationary supporting rings, both sets of rings
being of L-section and having radial notches in their flanges adapted when made
to coincide to give passage to a lug on a bolt, the flanges of the revolvable rings
obstructing the motion of the bolt except when their notches are so made to coincide
as described.
Dated this 5th do. 2 T
J. BOULDERSON,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.