Improvements in the Manufacture of Keys for Locks.
Year: 1899

page_text: Date of Application, 5th Aug., 1899 -Accepted, 16th Sept., 1899
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Keys for Locks.
I, CARL THEODOR SCHWEIZER, of 14A, Schlosserstrasse, Stuttgard, in the
German Empire, Agent General, do hereby declare the nature of my said inven-
tion 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 chiefly to a new or improved process for the manu-
facture of keys, or of key bits, and consists in drawing or rolling sheet metal
strips so as to obtain sectional forms corresponding to those of the key bits
required, the latter being finally formed by cutting the shaped sheet metal strips
into pieces of the required length.
And in order that my said invention may be particularly described and ascer-
tained, reference is hereby made to the accompanying drawings in which Fig. 1
is a side view of a shaped rod produced by drawing or stretching a bar corre-
sponding to the section required, by means of which Z shaped key bits are made
for solid keys.
Fig. 2 shows in section and elevation a key bit cut out of the shaped rod
shown in Fig. 1 and ready to be fixed to the key stem.
Fig. 3 shows another form of rod produced by means of a steel strip, and
having likewise a Z shaped bit, out of which bits can be cut for solid as well as
for barrelled keys.
Fig. 4 shows a
key bit cut out of the shaped rod shown in Fig. 3, and ready
to be fixed to a key barrel.
Figs. 5 and 6 illustrate a modification in the shape of the key bit and having
a hollow axis to be used for key barrels,
Fig. 7, shows a safety key for which the key bit of Fig. 2 is applicable.
Fig. 8, shows a hollow safety key to which the key bit of Fig. 6 is applicable.
Figs. 9, 10 and 11 show the various details composing the key, with the excep-
tion of the key bit.
The advantages realized by means of this invention are as compared with any
other mode of manufacture the following:-
1. Independently of the fact that greater accuracy is obtained, much lighter,
finer and less costly keys can be produced.
2. The wholesale manufacture of entirely finished key bits which form the
chief portion of a key and which may be readily replaced in case of accidents
such as broken bits.
3. The uniform manufacture of key bits of all dimensions of similar sectional
shape.
4. The avoidance of the hard labour hitherto required for making or cutting
key bits with a file, the new process of manufacture allowing of a number of
similar key bits being readily obtainable.
.
5. Notwithstanding its slight profile this new key bit is much stronger.
This is a matter of importance owing to the well known fact that the forcing

page_text: of a lock by means of skeleton keys is much more difficult in locks which have
a narrow instead of a large key hole.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:―
In the manufacture of keys made in several parts or pieces the application and
use of metallic bars or rods having the sectional form of the key bits required to
be manufactured and obtained by drawing, stretching or rolling these bars or
rods and afterwards cut into pieces having the length of the key bits required
to be manufactured, and being fitted in any suitable manner to the stem or
barrel of the solid or hollow keys, substantially as herein described and illus-
trated by the drawings.