IMPROVEMENTS IN DOOR LOCKS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by William Morgan Brown at the Office
of the Commissioners of Patents on the 27th December 1882. Communi-
cated to me from abroad by Oscar Belger and Ferdinand Preller of Hanover
Germany
"
WILLIAM MORGAN BROWN Patent Agent of 38 Southampton Buildings London
"IMPROVEMENTS IN DOOR LOCKS [Communicated to me from abroad by Oscar
Belger and Ferdinand Preller of Hanover Germany]
This Invention of a new lock is based upon the principle that the ordinary
spring bolt can be secured in its locking position, by a special locker arm, so that it
is impossible to withdraw the spring bolt by means of the latch and to open the
door. As shewn by the annexed Drawing, the spring bolt a carries an arm against
the end a of which presses a spring of any shape with the tendency to keep the
spring bolt in locking position Sheet 1 Figure 2. By pressing down the latch, a
cam d. fitted to the latch tube e is brought in to the position, as shewn by Figure 3.
This cam & operating against the end a¹. of the spring bolt moves the spring bolt
against the spring in ordinary manner and pushes the spring bolt into the
interior of the lock-case g. A stud l. rivetted to the bottom plate of the lock case
limits the stroke of the spring bolt and cam d. A shaft c. from which a locker
arm bis projecting, is placed inside the tubes e. and f in such a manner, that it
may be turned for a determined angle (as shewn by Figures 4 and 2) quite
independently from the movement of the cam d. and the latch tubes e. and f. which
are provided with a corresponding cut out c¹. (Figure 1-4) for this purpose. The
locker arm b. when not securing the spring bolt, is kept in a vertical position
(Figures 3 and 4) by a spring i. till its shaft c. is turned by means of a key set on
one of the ends. The annexed Drawings shew these ends to be square but they
may have any shape, more or less complicated, corresponding to a key bit which is
formed differently for each lock. Figure 2 shews locker bar b in a nearly hori-
zontal position which prevents the spring bolt a from being moved back, so that it
is quite impossible to open the door by means of the latch. In this position the
locker arm is secured by a spring and its stroke is limited by a catch a².
projecting from the spring bolt. The spring k may be dispensed with, and then
while for limiting the stroke in the opposite way a stud is rivetted to the cover
plate, the spring bolt will be provided with a small elevation receiving therein the
locker arm.
Figures 5 and 6 shew in which manner the two latch tubes e. and f. are con-
nected. The part of the tube f. being in the lock case is provided with a projecting

page_text: piece f. which enters into a corresponding cut out e' of the tube e. On the outer
ends of the latch tubes, the latches may be fitted in any convenient manner, and
the ends of the tubes may be covered by small covers, to keep off the dust from
the end of the shaft c.
Sheet II shews a modification of the lock. The spring bolt a is kept in locking
position by a spiral spring h. (Figures 1 3. 4) and its stroke is limited by a stud ĭ.
placed in a small slot of the said spring bolt. Each of the latch tubes e. and fis
provided with a cam d, (Figure 2) connected with the end of the spring bolt by a
connecting rod 8 so that the latch, when turned brings the spring bolt out of the
locking position (Figures 1 and 4) into the opening position (Figure 3). The bolt c
serves exactly the same purpose as it does at Figure 1-7. When the locker arm b.
is not secured in the spring bolt, it is held by the hook end pl. of the arm p., and
the spring i. as shewn by Figures 1 and 3. The bolt c when turned independently
of the movement of the latch brings the locker arm b into the position shewn by
Figure in which position the extremity of the locker arm 6 butts against the
edge a'. of the spring bolt and prevents the latter going backwards unless the
bolt c, is turned back towards the end of the arm p by means of a key.