Year: 1889

page_text: [Communicated from abroad by HUGO BONNINGHAUSEN, of Detroit, Michigan,
Gentleman, and CHARLES LOUIS SPIER, of Brooklyn, New York, Gentleman,
both in the United States of America.]
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
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 new and useful improvements in locks for double doors.
In the present construction of ordinary locks for double doors, one half of the door
is generally secured in close position by bolts, while the principal half of the door,
which is intended for constant service, is provided with the ordinary door lock.
The object of the said invention is to provide the supplementary half of the door
with an automatic device, which locks or unlocks such half every time the principal
half of the door is locked or unlocked, thereby saving the trouble of operating the
locking device of the supplementary half of the door.
The said invention consists in an automatic locking device for the supplementary
half of the door, which firmly holds that half in close position when the principal
half is closed, and which automatically unlocks when such principal half is opened,
all as more fully hereinafter described and shown in the accompanying drawings, in
which
Fig. 1 is a perspective view of the folding door provided with my improved
lock.
Fig. 2 is a detached perspective view of the lock, with the corner of the door to
which it is secured.
Fig. 3 is a vertical cross-section of the door with the lock in side elevation.
Fig. 4 is a vertical section of the door and lock.
Fig. 5 is a detached perspective of the casing of the lock.
Fig. 6 is a detached perspective of the back plate of the casing.

page_text: Fig. 7 is a detached perspective view of the spring bolt mechanism of the lock.
Fig. 8 is a detached perspective of the stop and keeper of the bolt.
A is a casing. Bare the flanges on the casing for securing it in position on the
upper inner corner of the supplementary door. C is a bolt slidingly secured in the
casing. D is a lateral curved arm-on the inner end of the bolt. E is a retracting
spring of the bolt which normally keeps the bolt retracted within the casing. F is a
crank shaft journalled in bearings a, b, transverse with the casing. G is a crank
formed on the inner end of the crank shaft within the casing and adapted to engage
into a notch c, formed in the arm D of the bolt. H is another crank formed in the
crank shaft outside the casing, preferably integrally with the crank shaft. I is a back
plate adapted to fit into the opening back of the casing to retain the parts therein in
position, and this back plate is provided with a guide arm d, which engages into an
aperture e; formed in the rear end of the arm of the bolt to guide the bolt in a
straight line. To secure the back plate to the casing, I provide the casing with a few
burrs, which in peening over are adapted to secure the back plate. K. is the keeper
of the bolt secured to the door jamb in suitable relation to the bolt and L is a stop.
formed integrally with the keeper K. M is a suitable lock secured on the principal
half of the door.
In practice, the parts being constructed and arranged substantially as described and
shown, the lock is secured to the upper corner of the supplementary door and in such
relation to the principal door that in closing such latter door it strikes the crank H,
and thereby actuates the bolt through the medium of the parts described to project
into its keeper against the action of the tension spring, which, in opening the door,
immediately retracts the bolt into its normally retracted position..
The crank H is sufficiently curved forward into the path of the principal door to
impart to the crank H the necessary amount of motion to project the bolt; and to
prevent the door from being marked from the impact with such crank, I provide the
principal door with the striking plate N. Thus it will be seen, that if the lock M of
the principal door is closed, the supplementary door is also firmly locked automatically,
and if the principal door is unlocked the supplementary part of the door is unlocked
automatically. The advantage of my construction if applied to cabinets, book-cases,
closets, etc., where generally folding doors are applied, or to double windows, is obvious,
as in such applications the discomfort and trouble usually experienced of manipulating
'ordinary bolts, which are often out of the reach of the operator, and the difficulty of
operation are entirely avoided.
While I have specified some of the applications of any invention, I do not intend
to confine myself to such applications alone. The same locking device described may
be applied to the lower corner of the door as well, especially where the doors are of
great height.
Having now particularly described and ascertained the nature of the said
invention 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,
1. In a lock for folding doors, a locking bolt mounted on the supplementary half of
the door and adapted to engage with the door frame, in combination with the actuating
devices controlled by the half of the door to automatically retract and project said
bolt by the movement of opening and closing said principal half of the door, sub-
stantially as described.
2. In a lock for folding doors, the combination of the casing secured to the
supplementary half of the door, and locking bolt mounted therein and adapted to
engage the door casing, the retracting spring of the bolt and the crank projecting
from the casing into the path of the principal half of the door, and having actuating
connection with the bolt, substantially as described.
3. In a lock for folding doors, the combination of the casing, the sliding bolt
provided with the notched arm, the crank shaft journalled transversely in the casing,
the crank arm on said crank shaft engaging with the arm of the bolt, and the crank
formed on the crank shaft outside of the casing, substantially as described.

page_text: 4. In a lock for folding doors, the combination of the casing A, provided with
the flanges B, the sliding bolt C, the curved arm D, provided with the notches e, c,
the retracting spring E, the crank shaft F, the crank G engaging into the notch
C, the
crank H, formed on the crank shaft F, outside the casing, and the back notch e, the
parts being arranged and constructed to operate substantially as described.
5. As a new article of manufacture, a lock for double doors consisting of a
enclosing frame or casing, a sliding bolt secured therein, the spring arranged to
normally retract the bolt, the crank shaft journalled in the casing, the crank secured
upon the said crank shaft within the casing and engaging with the bolt, and a crank
on said crank shaft outside the casing, substantially as described.
6. In a lock for folding doors, the combination of the principal door provided with
the striking plate N, the supplementary door, provided with the locking bolt having
a retracting spring and an actuating crank arm projected into the path of the principal
door, substantially as described, and the keeper K, secured to the door frame, and·
provided with the stop L, substantially as described.
Datad this 1st day of January 1889
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.