IMPROVEMENTS IN AND RELATING TO DOOR LOCKS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 6th July 1883. Communicated to
. him from abroad by Edme Augustin Chameroy of Paris; France
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN AND RELATING TO DOOR
LOCKS [A communication to him from abroad by Edme Augustin Chameroy
of Paris; France]
This invention relates to improvements in door locks.
In the manufacture of cheap locks, that is to say, those ordinarily employed for:
doors of all kinds, no provision is made for obtaining absolute security against the
use of false keys or picks. Locks having movable wards are more difficult to pick
than others but their cost, as heretofore made, is relatively high being often three,
four, or five times as much as that of ordinary locks.
The present invention is chiefly designed to improve ordinary locks in such a
manner that if any key other than the true one is used, it will turn freely to the
right or left but without producing any effect upon the bolt.
I will now proceed to describe a lock having my said improvements applied
thereto.
I provide a metallic box or case for. containing the mechanism which consists of
the following parts, that is to say.
A main bolt having beards or toes on its lower surface between which the key
acts whether inserted from the outside or inside of the door, and also having square
notches or openings in its upper surface.
A tumbler secured at one end to the case and carrying at its free end a down-
wardly extending lug, also having an extension against which the key strikes to
aise the same. This extension may have notches upon its edge.
A spring which acts to cause the tumbler and the aforesaid extension to hold the
ug in the notches in the upper part of the bolt.
A "dormant
knob.
"
or small bolt which is arranged to be operated inside the room by
A pivotted bent lever for enabling the dormant bolt to be operated from the
utside.

page_text: A metallic disc pivotted to form an excentric and whose axis of rotation is the
stem of the key. The periphery of this excentric is a perfect circle and has a
V-shaped groove therein.
Circular steel wards which are secured to the aforesaid excentric disc. The web
of the key is made with the proper clefts or passages for these wards and the
special arrangement of these wards forms the most important part of the present
invention.
A plate rivetted behind the bolt and whose lower part is pointed in the form of
a V to slide in the peripheral groove of similar form in the excentric disc.
A bent lever rivetted to the bolt. The horizontal part of this lever, like the plate
above mentioned, slides in the peripheral groove of the excentric disc so that it is
enclosed at top and bottom.
A spring pressing against the periphery of the disc to prevent its rotation when
the proper key is used.
A spring for pushing forward the dormant bolt when the knob is released..
An aperture for inserting the key from the outside and a separate aperture for
inserting it from the inside.
The proper key, being inserted from the outside of the door, may be turned
without difficulty either to the right or to the left and will readily pass over the
wards; the bolts will thus be properly. operated. If however, an improper key
should be inserted it may be turned to the right or left but in turning will carry
the wards with it and cause the excentric disc to rotate. In this movement around
the improper key the lower projecting part of the disc will cause the plate behind
the bolt, and consequently the bolt itself to which it is fixed, to rise, and as soon
as the said key has made half a turn the beards and the extension of the bolt
against which the key should act will be placed out of its reach. As the movement
continues, the excentric, then acting upon the lower part of the bent lever, will
bring back the bolt to its first horizontal or normal position without the improper
key having had any effect. This movement of the excentric takes place in both
directions and produces the saine effects either way.
Any key which may be applied, other than the one made spécially for the lock,
will have no other effect than to raise the bolt and place out of reach all the parts
required to be operated for withdrawing the bolt. A pick will have the same effect
as an improper key.
In some cases I propose to connect the disc with a gong or bell in the room so
that if an improper key or instrument should be used the attempt will be notified
by such gong or bell. In such case the proper or true key would not cause the
bell to operate for the reason that it does not impart any motion to the excentric.