An Improved Safety Lock for Safes, Strong Boxes, Doors, and the like.
Year: 1896

page_text: Date of Application, 11th Dec., 1896-Accepted, 20th Nov., 1897
COMPLETE SPECIFICATION.
An Improved Safety Lock for Safes, Strong Boxes, Doors, and
the like.
(A communication by VITTORIO D'ETTORRE of 6 & 7 Via Collegio Romano of
Rome in the Kingdom of Italy, Locksmith.)
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for Foreign
Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street, Manchester, both
in the County of Lancaster, 118 New Street, Birmingham, in the County of
Warwick, and 322 High Holborn in the County of Middlesex, Civil Engineer,
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 fol-
lowing statement:-
.
This invention has for its object to render impossible the separation of the
two wings of a door or grating, or of a single wing of the embrasure of the door
of a house, strong box safe, trunk, or any article of furniture without the use of
a key.
The invention consists of a safety lock having a bolt in the form of an are of a
circle mounted in a casing of circular form arranged in the box of the lock. This
bolt is adapted to be turned on its centre by means of a key in such a way that
on emerging from the case of the lock it engages in a hasp staple (stirrup) or
the like fixed in the embrasure or the opposite wing. In order that the key may
actuate the circular bolt it must first lift an indefinite number of plates provided
with teeth which penetrate into a groove or notch of the bolt with the object of
fixing the latter in its extreme positions. The lifting of the plates is obtained
by means of openings formed in the plates themselves into which engage the
various projections of the double bits of the key.
The safety lock forming the object of the present invention is shown in the
accompanying drawings, in which,"
Figure 1 shows the complete lock with the cover plate removed;
Figure 2, the same lock with the bolt and the piece for guiding it removed;
Figure 3, a similar view without the plates;
Figure 4 is a view similar to Figure 1, excepting that it shows the bolt in a
locked position.
Figure 5 is a key with double bits;
Figure 6 shows the lock applied to a door.
In all these figures the same letters and numbers represent the same parts.
The case A of the lock is of the ordinary shape and is provided with holes for
the passage of the screws intended to fix it to a door, piece of furniture or the
like. In the interior of the case the bolt B is mounted. This has the form of
an are of a circle larger than a semicircle, and in its rotation slides on projec-
tions 1 fixed on the bottom, and is guided by a piece C also having the form of
an arc of a circle which is fixed by screws to the bottom of the case. An arm 2 in the
form of a cross terminated by a cap 3 placed exactly in the diametrical centre

page_text: of the circle of the bolt is fixed solidly to the bolt B. This cap has a slot 4
(Figure 4) intended for the passage of the bits of the key F, and in its lower part
two stops which the projections of the bits of the key engage when the circular
bolt is turned on its diametrical centre. The sides 6 of the cross 2 serve to arrest
the course of the bolt B either in opening or in closing the lock.
Plates E are placed below the cross arm 2, which plates have a central open-
ing 7 of a form capable of being actuated by the projections of the bits of the
key F, and two slide slots 8 to receive studs 9 serving as guides in such a way
that the plates can be displaced in a vertical direction only falling down by
their own weight. Finally these plates are terminated at their ends by teeth 10
intended to enter the notches 11 of the bolt B with the object of holding the latter
in place in its extreme positions when the lock is open or closed. A rectilinear
horizontal bolt H, Figure 3, is added to the safety lock having a circular bolt,
which bolt H may be actuated by hand by means of a handle 12 projecting
from the lock, Figure 6, or by one of the projections of the key which, on bearing
against the extremity of an arm 13 of a lever 14, pushes the bolt H against the
action of spring 15. This same lever 14 has also an arm 16 provided with teeth 17
intended to penetrate notches 18 in the plates E with the object of holding the
latter in place during the movement of the rectilinear bolt H.
The double bits key F, Figure 5, has end projections 19 and 20 intended to
actuate the two bolts, and intermediate projections 21 intended to actuate the
plates. It is quite understood that there should be as many intermediate pro-
jections on the key as there are plates in the lock.
The support or plate D, fixed in the embrasure or on the wing of the door
opposite to the one on which the lock is fixed, is formed with two openings, one 22
intended for the passage of the circular bolt B and the other 23 to receive the
spring bolt H.
The working of the lock is as follows:-
When open, the bolt B is entirely lodged in the case of the lock whilst the
bolt H urged by the spring enters the openings 23 of the plate D. In intro-
ducing the key through the slot 4 of the cap 3 the intermediate projections 21
register with the plates E, whilst projection 19 corresponds with the stops or
contacts under the cap 3, and the projection 20 lies in the plane of the arm 13
of the lever 14.
By turning the key one quarter turn (that is to say before the projection 19
reaches the stops or contacts under the cap 3) the intermediate projections 21
lift the plates to such an extent as to allow of the teeth 10 coming out of the
notch 11. At this moment the bolt B is free to turn on its centre which motion
is effected during the following two quarters of a revolution of the key by the
action of the projections 19 which push the stops of the cap 3.
Towards the end of this movement the plates E drop downwards and the teeth 10
again engage in the notch 11 of the bolt, which is thus held in place in its shot
position. When is is desired to open the lock, on introducing the key as in the
previous case the first quarter of a revolution lifts the plates E and allows the
bolt to revolve on its centre, which motion is effected during the following half
revolution of the key, but towards the end of this half revolution, the projec-
tion 20 of the key encounters the end of the arm 13 of lever 14 and pushes inwards
also the bolt H against the action of spring 15 and the whole lock is thus opened.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is:-
1. An improved safety lock characterised by a circular bolt in place of the
usual rectilinear bolts with the object of preventing the separation of the two
locked wings of a door, applicable also to strong boxes, doors of all kinds, gratings,
furniture, trunks and the like, substantially as hereinbefore described.

page_text: 2. The general construction and combination of parts taken as a whole forming
he improved safety lock substantially as hereinbefore described and illustrated.
Dated this 10th day of December 1896.
WM. P. THOMPSON & Co.,
Agents.