Improvements in Locks.
Year: 1893

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by THEODOR KROMER, of 42, Lehnerstrasse, Freiberg,
Baden, in the Empire of Germany, Manufacturer.]
Improvements in Locks.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 locks with bolts operated by turning-handles, and has
for its object to simplify such locks and to render it difficult by special forms of
tumblers to copy the key.
Instead of opening the bolt by causing one part of the same to pass into the
tumblers the arrangement is reversed, inasmuch as the tumblers move into a fork or
between other fixed points of the bolt. By this means the whole mechanism can be
very much simplified and made strong.
The tumblers are always moved and guided like a slide; they are guided in
straight lines or slight curves and pushed forwards by springs, which latter are
represented in Figure 10 of the accompanying drawing.
By a is designated a quadrangular body provided with parallel channels a¹ a¹ in
which the two forks 6 6 of the bolt b are adapted to slide.
The tumblers care guided in a depression of the body a and in the closed
state project into the channels a¹ a', Figures 1 and 2.
By this means they prevent directly the drawing back of the bolt b, as the ends b
of the forks b¹ 61 bear against the tumblers.
Of these tumblers c some lock upwards and others downwards, the former being
designated by c¹ and the latter by c² in the drawing. Their number is optional
and each tumbler corresponds to an operative step of the key.
With the object of rendering it difficult to copy the key, false steps may be
provided.
0.
When the lock is to be opened the key is inserted, and by turning it the tumblers
are moved back into the body a so that their ends are flush with the sides of the
channels a¹ a¹.
In this position of the tumblers the bolt can be moved back (Figure 2). But in
order to enable the key to be pulled out without requiring the bolt to be closed the
two forks have recesses g with inclined planes g¹ into which the ends of the tumblers
can pass.
Accordingly the key may be brought back to the closed position and pulled out,
while the tumblers are closed and placed in the recesses
When closing the bolt the tumblers are forced back by the inclined surfaces g'
and advance again when the bolt is in the closed position (Figure 1).
Instead of making the bolt fork-shaped it may bave any other suitable form, for
instance the rear part of the bolt may constitute a large plate provided with two
projecting parts which take the place of the forks.
To render it difficult to copy the key in the case of these tumblers their surface,
which is touched by the bit of the key, is formed in a special manner.
Up to the present time the keys and tumblers are so formed that the contact of
the step with the tumbler in the open position takes place at one point or in
a short curve k, Figure 7, which is at the front part or somewhat laterally on
the step.
In the copying of keys attempts are therefore made to accurately copy only
these front parts of the steps.
This conving is rendered
considerably more difficult if the contact takes

page_text: place in the open position at two points, which may be on the two sides of
the steps.
Figure 7 represents the arrangement heretofore employed.
Figures 6, 8 and 9 represent various improved forms; recesses are provided in
the tumblers which are constituted either by a straight line or by curves, and have
the characteristic feature that a recess is presented opposite the step with two
points of contact / and i.
This arrangement is of course also applicable to tumblers of any kind which are
suitable for the purpose.
Having now particularly described and ascertained the nature of my 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 :-
First. A lock with a bolt actuated by a turning-handle characterized by stopping
points on the bolt, which serve for locking the latter and can receive between them
the opened sliding-tumblers.
Second. For the purpose of rendering it difficult to copy the steps of the key the
formation of curves in sliding tumblers in such a manner that the tumbler is touched
at two points by the step of the key.
Dated this 8th day of Kebruary 1892
Dated this 8th day of February 1892
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant,