Improvements in Latch-locks.
Year: 1898

page_text: Date of Application, 2nd Aug., 1898-Accepted, 15th Oct., 1898
Improvements in Latch-locks.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by the Miller Lock Company, a corporation organised
under the laws of the State of Pennsylvania, United States of America, and engaged
in business at Frankford, in the City of Philadelphia, in the said State), and in
what manner the same is to be performed, to be particularly described, and ascer-
tained in and by the following statement:-
This invention relates to that portion of the mechanism of a latch-lock whereby
the bolt is retracted by the action of a key, the object of the invention being to so
construct such mechanism that it may be carried entirely by the cover plate of
the lock and will not project outwardly beyond the latter so that no opening need
be made in the door for its reception.*
This object is attained in the manner which I will describe with reference to
the accompanying drawing, in which Figure 1 is a transverse vertical section of a
latch lock constructed in accordance with the invention; Figure 2 is a longitudinal
section on the line wow Figure 1; Figure 3 is a sectional plan on the line
Figure 2; Figure 3 is an elevation of one of the fixed ward plates; Figure 4 is
a transverse section illustrating another construction of the latch-lock in accord-
ance with this invention; and Figure 5 is a sectional plan on the line
Y-Y,
Figure 4.
1 represents the cover plate of the latch-lock and 2 the latch bolt, which has at
its inner end a cross bar 3 for being acted upon by the arm, or lever 4, technically
termed the "roll-back," which is operated by the key in order to effect the with-
drawal of the bolt.
Projecting inwardly from the plat 1 are posts, or studs, 5, and engaging with
these posts, or studs, and secured in place by a cap-plate 6, at the inner ends of the
same, are fixéd washers 7 and fixed wards 8, the latter being constructed as shewn
in Fig. 34, for instance, so as to require the notching of the key 1* wherever one of
them occurs.
The washer 7, which is in contact with the plate 1 receives a projecting hub 9,
on the roll-back 4, so as to properly centre and retain the latter, a shoulder 10, on
said roll-back, serving, by contact with one of the posts 5, to limit the backward
movement of the roll-back, the forward movement of the same being limited by
the stoppage of movement of the latch-lock itself.
The entire mechanism, comprising the roll-back, washers, and tumblers, or
wards, is on the inside of the latch-lock, so that the said latch-lock can be secured
directly upon the face of a door, or other structure, without necessity, for forming
an opening in the said door or structure for the reception of the usual projecting
tumbler casing, the only opening which it is necessary to form in the door or
structure being that for the passage of the key.
The construction shewn in Figures 4 and 5, is one in which the roll-back is
operated by projecting fingers on the end of the key, no tumblers, or washers, beinơ

page_text: employed. In this case a countersunk opening in the cover plate 1, receives a
shouldered disc 11, to which the roll-back 4 is secured by rivetting, or in any other
convenient manner, the disc thus, in effect, constituting the hub of the roll-back,
and both parts having openings 12 formed therein for the reception of the project-
ing lugs, or fingers, at the end of the key.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is;-
1. A latch-lock having the roll-back carried by a supporting structure which
is mounted upon the cover plate of the latch-lock and does not project outwardly
beyond the same, substantially as hereinbefore described.
2. A latch-lock having a roll-back with a shouldered hub engaging with a bear-
ing which does not project outwardly beyond the cover plate of the lock, sub-
stantially as hereinbefore described.
3. The combination in a latch-lock, of a cover plate with a series of washers and
tumblers, or warda, secured upon the inner face of said plate, and a roll-back having
a hub fitting into a bearing in one of the said washers, substantially as herein-
before described.
4. A latch-lockihaving a cover plate, in combination with a roll-back and a series
of washers and tumblers, or wards, confined to the inner face of said cover plate,
substantially as hereinbefore described.
Dated this 2nd day of August 1898
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.