Improvements in Combination Letter Locks.
Year: 1891

page_text: Date of Application, 3rd June, 1891
Complete Specification Left. 3rd Mar., 1892-Accepted, 23th May, 1892
PROVISIONAL SPECIFICATION.
Improvements in Combination Letter Locks.
| JOHN MELTON BLACK of Tabernacle Street in the County of London
Gentleman do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in the combination letter lock such as used
in a bell punch as illustrated in Figs. 1 and 2 of the drawings of the Specification of
Letters Patent No. 6551 A.D. 1889 so as to render the bolt of the lock not liable
to be fraudulently withdrawn in the event of the letter rings being worn or the bolt
loose. This is effected by removing the top ring to which the bolt of the lock as
now constructed is attached and in so constructing this top ring as to be screwed
and fixed to the central inner pillar of the lock. This ring has a central opening
into which the head of the bolt of the lock is fitted and is so made that when the
bolt is home it cannot be raised or laid hold of. By this means attempts to
discover the letter lock of each ring by raising the bolt by wedges or otherwise are
frustrated.
The bolt can only be removed by a person cognizant of the combination letters
of the lock which being placed in line and the bolt head turned downwards the
bolt gives way and the lock is opened.
J. M. BLACK.
COMPLETE SPECIFICATION.
Improvements in Combination Letter Locks.
1 JOHN MELTON BLACK of Tabernacle Street Finsbury in the County of
London Gentleman 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 improvements in the combination letter lock such as
used on a bell punch instrument or the like as illustrated in Figures 1 and 2 of the
drawings of the Specification of Letters Patent No. 6551 A.D. 1889 so as to render
the bolt of the lock not liable to be fraudulently withdrawn in the event of the letter
rings or the bolt being worn or loose.
The improvements will be understood by reference to the following figures of the
drawings upon which letters of reference are marked on corresponding parts of all
the figures alike.
Figure 1 is a front view of the combination letter lock and bolt and top ring.
Figure 2 is a sectional view of the same.
Figure 3 is a view of the bolt of the lock.
Figure 4 is a plan view of the top or fixed ring.
A A A A are the 4 moveable rings of the lock having letters of the alphabet
stamped thereon and revolving on the standard C as usual in locks of this kind, the
standard or pillar C being attached to the object to be locked by the pin C¹.
B is the improved top ring screwed and fixed to the pillar C and having the
recess B² therein for the bolt head D' to rest thereon and groove B³ for the bolt D
to enter.
D is the bolt having wards thereon corresponding with the grooves D³ in each
of the internal toothed rings of the letter rings as usual in the ordinary combination
letter locks, but having a semi-circular head D' which fits loosely in the recess B*
of the top ring as shown in Figure 2 of the drawings.

page_text: To fasten the lock the letters on the four rings A A A A (selected and specially
set to open and close the lock) are placed in a line corresponding with a notched
mark at the base of the lock as usual in locks of this kind, that is to say in such a
position that the grooves B³ in each of the letter rings correspond with the letters
selected to open and close the lock and are in the same line, so that the bolt D can
be pushed home and the bolt head D' enter the recess B2 in the upper ring, when
the letter rings are moved in different positions to mask the combination letters
which allow the bolt to be withdrawn and so the bolt becomes fastened by the
grooves B³ in the four letter rings being no longer in the same line.
To open the lock the letters on each of the 4 rings which allow the bolt to be
withdrawn are set in a line with the notched mark above mentioned when the lock
is inverted and the weight of the semicircular bolt head D of the bolt allows the
bolt to give way and so opens the lock.
The feature of these improvements is that the head of the bolt cannot be laid
hold of or removed from its position when locked nor the combination letters of any
of the moveable rings discovered by artificial means and that the lock can only be
opened by the actual letters of the combination being known.
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
1. The improved arrangement of bolt in combination with the moveable rings
and pillar of the ordinary combination letter lock as described herein and shown in
Figures 1, 2 and 3 of the drawings.
2. The improved arrangement of top ring to screw upon the pillar of the ordinary
combination letter lock having a recess therein for the bolt head of the bolt to enter
as described herein and illustrated in Figures 1. 2 and 4 of the drawings.
3. The combination of the improved bolt D and top ring B in combination with
the letter rings and pillar of the ordinary combination letter lock as described.
herein and illustrated in Figures 1 and 2 of the drawings.
Dated this 3rd day of March 1892.