Improvements in and connected with Door Fastenings.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with Door Fastenings.
I BENJAMIN RICHARD BAKER of 31 Barford Street, Islington in the County
of London, Carpenter, do hereby declare the nature of this invention and the
manner in which the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates to certain improvements in and connected with door
fastenings and has for its object to provide apparatus which shall be more specially
applicable to the exit and other doors of theatres, public halls, and like buildings
wherein panics may occur. By my apparatus such doors can be securely fastened
so that they cannot be opened from the outside but they will be liberated and free
to open immediately any pressure is applied from the inside either directly or
indirectly to the fastening.
According to my invention I cause each locking bolt to be acted upon by the
force of gravity, or a spring, or a weight, and I arrange that the force shall either
constantly hold the bolt back from locked position so that it must be pressed there-
into, or, that the said force shall constantly hold the bolt forward in locked position.
In the first case the bolt is maintained in its locked position by a stop bolt engaging
suitably with it, or if there be a pair of bolts engaging between their heads, said
stop bolt having itself an automatic quick return but adapted to be retained in
forward locking position by a catch lever with a tail arranged in such manner that
any force applied to the said tail from the inside of the door or doors will release
the catch lever, and the bolt or bolts will then instantly fly back and unlock the
door or doors.
In the second case the bolt or bolts is or are normally held forward in locked
position by spring or equivalent force and so maintained by the same arrangement
of automatic return stop bolt and catch lever above indicated and hereinafter set
forth, but in this case each bolt head and its striking plate are bevelled on their
outer sides so that when the stop bolt is released and automatically withdrawn as
indicated on pressure being applied to the door or doors the locking bolts will
recede from and clear their striking plates, so that the door or doors can be forced
open at once.
The first above mentioned arrangement is the more sensitive and reliable for
which reasons it is preferred, and I will now fully describe it in reference to the
accompanying drawings in which
Figures 1 and 2 are elevations showing a pair of bolts and the parts in locked
and unlocked positions respectively.
Figure 3 is a section on line 1-2 of Figure 2 showing also in part a pair of
swing doors and an operating cross bar.
Figure 4 is a part inside elevation of a pair of doors having my invention applied
thereto; and
Figure 5 is an elevation showing the application of my invention to a single bolt.
In all these figures like letters indicate similar parts.
A. A. are a pair of bolts arranged in the same straight line the quick return force
being a spring a applied as shown, or otherwise in suitable manner; a¹a¹ are
guiding pins in slots.
B is the intervening stop bolt sliding in guides, and 6 its return spring; these
springs a. a. b. constantly tend to keep the bolts in the position of Figure 2.
The bolt B has a head b¹ of a size equal to the travel of the bolts AA, and on
its upper side a catch c is formed with which engages the nose of a catch lever C
disposed adjacent to bolt B and centred at c' on the door; it has a tail c³ normally

page_text: pressed outwards by spring c³ and the whole is or may be enclosed in a casing
such as d.
To lock the door the bolts A A are forced forward into their sockets and the
head b' of bolt B intervened between them in any-convenient manner compressing
the springs a. a. and 6 until the nose of-catch-lever C drops into the catch cin
which position it is ratained by spring c. Referring to the case of a single bolt
illustrated in Figure 5. it will be seen that the stop bolt B simply engages in a
recess or catch a in bolt A and the lever C is 'shown in a-position -requiring a
downward force to operate it; the other parts all remain the same.
Thus in either case the door is held locked and it will be obvious that the least
pressure applied to the tail of lever C will free the catch a when all the
bolts B. A. A. will at once be forced back by their respective springs and the door
released. For a single door a bar such as E may be applied across the door
covering the above described apparatus; it is hinged at one end to the door as
at d and pressed from the door by spring e and guided by slotted plates and pin e'.
For a pair of swing doors as illustrated Figures 3 and 4 two such bars E E
may be carried across them, the one E (operating the catch lever C) being
arranged beneath the other one E' as illustrated, Figure 3, at so that pressure
applied to either of them will free the bolts.
I would have it understood that the details hereinabove set forth may be varied
to suit particular cases without departing from the nature of my said.inven-
tion, and
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 door fastening consisting of an automatic return bolt arranged to be held
in locked position by an automatic return stop bolt adapted to be retained in
locking position by a catch lever until pressure is applied thereto substantially as
set forth.
2. Fastenings for doors consisting in the arrangement of an automatic_return
lock bolt A, or a pair of same AA in the same line, and adapted to be held in
locked position by an automatic return stop bolt such as B controlled by a catch
lever the whole operating substantially as described and illustrated.
3. In fastenings for doors the combination with spring return lock and stop
bolts A B and catch lever C having a tail c³, of the operating bar E or bars E, E,
all arranged and adapted to operate substantially in the manner and for the purposes
hereinabove set forth.
Dated this 9th day of October 1891.
J. C. CHAPMAN,
Chartered Patent Agent, 70, Chancery Lane, London, for the Applicant.