Improvement in Bolts and Fastenings for Doors of Theatres and other Public Buildings.
Year: 1891

page_text: Date of Application, 2nd Nov., 1891
Complete Specification Left, 11th June, 1892-Accepted, 13th Aug., 1892
PROVISIONAL SPECIFICATION.
Improvement in Bolts and Fastenings for Doors of Theatres and
other Public Buildings.
ROBERT ALEXANDER BRIGGS New Empire Palace Office 31 Nicolson Street
Edinburgh Civil Engineer do hereby declare the nature of this invention to be as
follows:-
The bolts on the door are connected by means of levers or cranks or a combina-
tion of levers and cranks with a push piece or push rod contained in a box affixed
to the stile of door so that in the event of pressure on the inside being applied to
the push piece or push rod the bolts are automatically withdrawn from the door
head and sill and the doors set free the reverse action shoots the bolts and
thoroughly secures the door.
Springs are sometimes used to assist or retard the action of the push piece and
levers and to hold them in position when door is opened.
Metals are entirely used in construction.
Dated thig 31st day of October 1801
ROBERT ALEXANDER BRIGGS.
COMPLETE SPECIFICATION.
Improvement in Bolts and Fastenings for Doors of Theatres and
other Public Buildings.
I, ROBERT ALEXANDER BRIGGS of the New Empire Palace Office, 31 Nicolson
Street, Edinburgh, Civil Engineer and Surveyor, do hereby declare the nature
of my invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement in writing,
reference being had to the accompanying drawings
-
This invention has reference to and comprises a new or improved mode and
means or arrangement and combination of bolts and fastenings for being applied
to the doors of theatres and other public buildings; whereby in the event of fire,
alarm, or panic within the building, the doors will automatically open by the
exercise of a slight degree of pressure on a transverse rod behind each door, and
permit the safe and easy exit of the persons within the building.
The bolts on the door are connected by means of levers or cranks or a combina-
tion of levers and cranks with a push-piece or push-rod contained in a box affixed
to the meeting stile of door, so that in the event of pressure on the inside being
applied to the push-piece or push-rod the bolts are automatically withdrawn from
the door-head and sill, and the door set free; the reverse action shoots the bolts
and thoroughly secures the door.
Springs are sometimes used to assist or retard the action of the push-piece and
levers and to hold them in position when the door is opened. Metal is entirely
used in construction.
And in order that the full nature of my said invention and the manner of
performing or carrying the same into effect or practice may be properly understood,
I have hereunto appended an explanatory sheet of drawings in which the same
reference letters are used to indicate corresponding parts in all the figures where
shown.
Figure 1 is a side or edge elevation showing broken away, my improved locking

page_text: bolt fastenings as applied to single or double doors of public buildings, the improved
fastenings being shown in their unlocked or inactive position; and
Figure 2 is a front elevation corresponding and at right angles to the view shown
in Figure 1, and looking on the inside of the door, while
Figure 3, is a sectional edge elevation corresponding to the view shown in
Figure 1, but showing the sliding bolts and improved operating fastenings in their
locked holding position.
Referring to these drawings.-The vertical sliding or shooting bolts a a', are
preferably made tapered at the ends to enter sockets in the frame work at the top
and bottom ends A A" of the door A respectively, and may be assisted in their
action by light helical springs a' placed in boxes a secured to the inside of the
door A, and are by my improvements connected at their inner ends by pins at all
to the one arm b of the two bell crank levers bb¹. These levers bare each
fulcrumed on pins at 611 within the locking lever chamber A³, sunk in the door A,
and are formed with slots at 62 on their inner arms which engage with a trans-
verse pin 3. This pin 3 also passes through the inner end of a forked push
piece or spindle c, and its ends slide in horizontal slots A³, formed in the sides
of the box A', and so assist in guiding the push piece c in its traversing motion.
This push piece is preferably made hollow and works in a socket c¹ on the
cover plate of the box A2, and has a large head or knob c² at its inner end outside
the socket C. This inner head has a slightly oblong hole c" on its one side,
as seen particularly in Figure 3, into which the outer free end C¹ of a horizontal
long tube lever C is inserted, this lever being hinged at its other to a stud C³
screwed to the inner hinged side A' of the door A. The hollow push-piece c
has preferably mounted within it a small spring locking lever d d fulcrumed at d",
having its square locking end or arm d pressed down by a spring d to lock the
push-piece in its out position as shown in Figure 3; while the other arm d¹
is curved and actuated by the first pushing in motion of the end C¹ of the
lever C, to unlock the lever catch d 'd' and then press in the push-piece and
joint arms b¹, 1, of the levers bb, and unlock the bolts a a', as shown in this
position in Figures 1 and 2, the springs a² assisting in this action, the expanded
or lengthened position of the lever arms b¹ b', on opposite sides of their
fulcrums tending to retain them in their locked or unlocked positions, until
actuated by drawing or pushing the lever C on the inside of the door A
irrespective of the springs a² and spring catch d to d². Thus it will be seen
that the door A will be firmly locked when the mechanism is drawn to the
position shown in Figure 3, and cannot be opened from the outside; but as
soon as a crush or pressure of persons takes place inside the door they neces-
sarily press the lever C and automatically withdraw the bolts a a' and swing
open the door, all as hereinbefore described.
6:
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is.―
First. The construction or arrangement and combination of the parts of safety
locking and releasing lever mechanism for the doors of theatres and other public
buildings, substantially as herein described, in reference to and shown in the
accompanying drawings.
Second. In doors for theatres or other public buildings, the actuating of their
vertical locking bolts by bellcranks of a reverse angling action from a push
lever C and rod c on the inside of the door, substantially as herein described in
reference to and shown in the accompanying drawings.
Dated the 10th June 1892
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.