Improvements in Locks for Doors and the like.
Year: 1897

page_text: Date of Application, 14th Dec., 1897-Accepted, 14th May, 1898
Improvements in Locks for Doors and the like.
I, THEODOR KROMER, of Freiburg i/B, in the Empire of Germany, Lock Manu-
facturer, 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:-
:-
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In locks of the kind known as Chubbs locks" it frequently happens that the
tumblers become clogged with resinous matter, which fact has led to the con-
struction of the tumblers in such a manner as to be forcibly moved. by keys with
double bits in connection with a rotary lever handle.
This construction, however, presents the great disadvantage that the key is
prevented from executing a complete revolution so that the key cannot be with-
drawn, until the bolt has again been moved forward into locking position. As
regards their constructional arrangement, these locks have the great disadvantage,
that is very difficult and costly to so work the tumblers as to exactly correspond
to the respective opposite steps of the key bits.
These disadvantages are removed by the improvement hereinafter described and
illustrated in the accompanying drawing.
Referring to the said drawing 1 is the bolt of a Chubb-lock, moved by the key.
itself (and not by a rotary handle), 2 is a recess in the bolt with the portion 3
acted upon by a single-bit key; 4 are the Chubb-lock-tumblers provided with
slots as shown so adjusted that the projection 5 of the bolt can pass into the
locking position irrespective of whether the bolt be in its open or closed position.
The face plate has two horizontal key holes arranged opposite each other.
The tumblers are provided at their lower part with anchor-shaped heads 6 and 7,
the level top surfaces of which coincide with the bottom edges of the key holes.
It is not absolutely necessary that these surfaces should lie exactly in the hori-
zontal plane, but may, on the contrary, be slightly inclined in an upward direction
in order to reduce the so-called "powder chamber."
Now, in order to open the lock, the key is inserted into the left hand key hole
and turned to the right (see Figures III and I). As soon as the bolt is brought
into complete opening position, the tumblers are forced down into the closing
position by the bit of the key which depresses the head 7 of the tumblers, where
upon the key can be withdrawn. (Figure II). For the purpose of closing the
lock, the key is inserted into the right hand key hole and is given a left hand turn.
By this operation the bolt is moved back and the key-bit passes the tumblers
into the locking positions by depressing the anchor 5 and by thus passing into
position opposite the left hand key hole, the key can be withdrawn (see Figure III).
Whether the bolt be occupying its open or closing position, is found out by
the fact that the key admits of being either inserted at the right or at the left
hand side, since otherwise the key comes into contact with the bolt. Between
each pair of tumblers and of substantially the same shape. are arranged thin
plates of brass not shown, these plates are made somewhat dish-shaped and are

page_text: pressed flat by the tumblers and thus exercise a pressure on said tumblers so that
they do not bear against each other.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
An improved Chubb-lock with elastic plates, arranged between the tumblers,
and a single-bit-key, the characteristic feature consisting in the arrangement of
two key holes, and of two heads provided on each of the tumblers.
Dated this 14th day of December 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, WC., Agents for the Applicant.