AN IMPROVED DOOR BOLT, AND BURGLAR ALARM TO BE USED IN COMBINATION THEREWITH
Year: 1884

page_text: COMILELE
DE ECIFICATION.
I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, Patent Agents, of
52 Chancery Lane, London, in the County of Middlesex, do hereby declare the
nature of said Invention for " AN IMPROVED DOOR BOLT, AND BURGLAR ALARM
TO BE USED IN COMBINATION THEREWITH and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following.
statement:-
"
My Invention relates to door bolts and its object is to so construct the same;
that when the bolt is shot, it cannot be operated so as to unlock the door by the
means of any tools or instruments inserted from the outside.
To this end, my
Invention consists in the combination with a door bolt of a spring or other
retracter which tends to throw the bolt back when it is shot to lock the door, an
operating thumb piece or slide detached from the bolt and so arranged that it may
be brought against the bolt for throwing it to lock the door, and a suitable
automatic catch which engages with the bolt automatically to hold it, when it is
shot, but which may be operated from the inside of the door to release the bolt
and allow it to be thrown back by the action of the spring or other retracter.
.
My Invention consists further in certain specific combinations, and details of
construction that will be specified in the claims hereto annexed.
My Invention is designed also for use with a bolt so combined with an alarum
that the latter will be automatically released and sounded upon the movement of
the bolt sidewise consequent upon the impingement of a tool upon it or of pressure
upon the door upon an attempt to open it by any unauthorized person.
In the accompanying Drawings, Fig. 1, is 'a front view of the bolt with the
casing in place, Fig. 2, shows the casing removed to expose the interior mechanism,
Fig. 3, is a longitudinal cross section on the line 3. 3. of Figure 2. A indicates
the casing of the bolt and A² the plate upon which the bolt and its attached parts
are mounted, both plate and casing being perforated at points a. Said plate and
casing are secured together by screws passing through holes b. Fig. 2, in plate A
into the edge of A. The perforations a, serve to admit screws by which the bolt
may be secured to the inside of a door, C, indicates the bolt proper which works

page_text: through a guide piece C² and is provided with a coiled spring C³ abuting at one
end against a collar C on the bolt and at the other against guide C or with
other suitable retracters so that when the bolt is thrown out into the position
shown in Figure 1, the spring will be compressed. The rear portion of the bolt is
provided with a plate I. having projections 13 against the back side of which may
engage a pin or shank D³ projecting downwardly from slide D. sliding in a slot
in the casing so that the bolt may be thrown forward against the action of the
spring C but cannot be thrown backward by said slide.
A pin . projecting upward from a varied surface on plate A² assists in guiding
the bolt. D³ indicates a retracting spring that serves to return the slide D. to its
normal position.
Formed in plate I. is a slot or recess I' with which an automatic sliding catch
bar E engages when the bolt is shot.
The bar E³ works in a guide slot formed in a raised portion of the base plate A³
and is provided at its upper end with a pin or projection j with which engages a
spring J. that tends to lift the catch or slide bar E³. A step or rebate is formed
on E at e. to engage in slot I².
-
E, indicates a small knob working in a slot in the casing and having a rounded
or beveled head upon the outside of casing A. and also provided with a spindle or
stem E that passes into a slot in Es so that E³ may be drawn down against the
action of the spring J. When the bolt is shot by the slide. D. the catch bar E³
engages automatically with the slot I and locks the bolt from backward movement
under the action of the compressed spring C³.
When it is desired to unlock the door, the button E. is moved downward thus
releasing the bolt when the spring C³ will throw it. back. The button E. as it
has a rounded surface cannot be operated by a wire or other instrument inserted
from the outside of the door, nor can the bolt be subjected to any retracting force
through slide D. since the same only engages with the bolt in such a way as to
enable the bolt to be shot to lock the door.
I have herein shown the bolt as combined with an automatic alarm that will be
set off in case the bolt be moved laterally against the force of a spring K. secured
to the bolt and resting against the inner surface of the casing A. The essential
parts of the alarm mechanism are as follows:-H. is a spring detent arm upon the
arbor of a wheel G³ to which arbor or wheel one end of the main spring is
attached while the other end is attached to a fixed stud upon the base
plate. O. is a catch plate having a step or catch at h. which the spring
arm engages and is locked when the alarm is wound up. F. is a handle or arm
upon the outside of the casing which is secured to the same spindle as H. and serves
to wind up the alarm mechanism..
A plate M, pivoted to plate O. allows the detent arm H to pass in the act of
winding up the mechanism, but when the mechanism is wound up will also permit
the arm to spring into engagement with the step h. The plate M has a curved
edge as indicated, and a spring S. which tends to throw said plate against the
stop N. and into position where, when the detent, is released and begins its
retrograde movement said detent will slide over such curved edge and will pass the
step 1. without engaging with the same. The bolt C. at the rearmost portion I. is
capable of a slight lateral movement and when the bolt is shot, a raised portion L.
of the portion I. is in position to engage with the spring arm H. and release the
alarm mechanism in case any lateral movement should be given to the rear portion
of the bolt, either by the insertion of a drilling tool or other instrument by any
unauthorized party, or by an attempt. to open the door when it is bolted. Gis the
escapement wheel of the alarm mechanism which serves to impart movement to the
bell-hammer B2 in the ordinary way, while B. indicates the bell mounted on
plate A³ in position coincident with an opening cut in the casing A. so as to allow
the sound to more readily escape. G. G indicates the well known device of a
geneva stop to prevent over winding of the driving spring for the alarm
mechanism.

page_text: I do not limit myself to any particular construction of sliding catch or lock for
automatically engaging with the bolt when it is thrown to lock the door, as many
others may be used in place of that shown for accomplishing the same purpose, viz.,
the automatic detaining of the bolt after it is thrown to prevent it from being
thrown back by the action of the spring or retractor until the catch is removed
from engagement with the bolt by the slide button or knob E. having rounded
head.
The slide D. De might be attached to the bolt or an extension J. but I generally
prefer not to do this as it would afford a means whereby the bolt might be subjected.
to a strain by a tool inserted through the door for the purpose of unlocking it.
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 combination with the sliding bolt C. and its retracting spring, of the
automatic sliding catch for holding the. bolt and the rounded head or button E. for
the catch, projecting through the casing and nearly flush with the outer surface of
the casing, as and for the purpose described.
2nd The combination with the bolt C. and spring C³ of the automatic catch
sliding transversely to the bolt and having a rounded head or operating button E.
projecting through the casing but nearly flush with the outer surface thereof, and
the independent operating thumb piece D. upon the exterior of the case having an
internal piece D2 adapted to engage with the bolt C. to lock the door but incapable
of acting on the bolt for the purpose of throwing it back.
3rd The combination of a horizontally and laterally movable bolt C. springs C³
K. detached operating thumb piece, and stud D. D2 so arranged that it may be
brought against the bolt for throwing it to lock the door, the automatic catch, and
a detent for an alarm mechanism placed in the path of the bolt when moved
laterally, as and for the purpose described.
4th The combination with the sliding bolt C. retracting spring C³ automatic
sliding catch Es of the knob or button E. and slide D..substantially as and for the
purpose described.
5th The combination of bolt C. spring C³ slide E³ spring J. and button E. having
stem or spindle E engaging with slide E³.
6th The combination with the bolt and its retracter, of a detached operating slide,
thumb piece, or similar operating device, arranged in the manner described to
engage with the bolt and throw it against the stress. of a retracting spring or other
suitable device tending to hold the bolt back, said thumb piece being incapable of
acting on the bolt in the same direction as the spring, and an automatic catch for
engaging with and holding the bolt against its retracter, as and for the purpose
described.
Dated this 6th dow of Mov &T 1991