Improved Self Lowering and Adjusting Metallic or other Fire Proof Material Shutters for Prosceniums of Theatres and Music Halls.
Year: 1887

page_text: Date of Application, 17th Sept., 1887
Complete Specification Left, 14th June, 1888
Complete Specification Accepted, 17th Sept., 1888
Improved Self Lowering and Adjusting Metallic or other Fire Proof
Material Shutters for Prosceniums of Theatres and Music Halls.
I FREDERIC BARNETT of No. 106, Queen Victoria Street City London Civil Engineer
do hereby declare the nature of this invention to be as follows:-
That as fires in Theatres nearly always commence on their stages it is of the utmost
importance that they should be there localized as long as possible both with the object
of reassuring the audience to induce a calm retreat and at the same time to improve
the chance of saving the auditorium.
To attain this end I establish above and just behind the Proscenium shutters of iron
plates or other suitable material wide enough to extend on each side nearly to the walls
of the building.
For choice these shutters are to be manufactured of quarter inch iron plates stayed
and strengthened with half round iron of sufficient substance.
At either end of these shutters will be established pulleys in which endless chains
will revolve corresponding with pullers established in the ground below the stage.
The upper shutters will be firmly attached to the outer side of the two chains
while to the chains on the opposite side the shutters below the stage will be similarly
fastened.
The shutters always above the stage floor when lowered will be of sufficient depth to
reach near the floor and being made of greater weight than the shutter below the
stage will so overbalance it that while descending gently by its own gravity lift the
lower shutter through an especial practical trap in the floor of the Stage till in rising
it come in contact edge to edge with the upper shutter and this effect will be almost
instaneously produced by liberating a, brake which has hitherto retained the upper
shutter behind and above the Proscenium, which Brake will be so arranged that it will
be able to lower the upper shutter and consequently raise the shutter from underneath
the stage when standing within or without the Theatre.

page_text: When the lower shutter unites with the upper the fire will be equally shut off
below as above the stage from communicating with the Auditorium for some time.
When the bottom shutter is not in use it will be so low sunk in the ground that it
will not interfere with the passage to or from the orchestra. The shutters will be
restored to their berths by inanual hydraulic or other power.
COMPLETE SPECIFICATION.
Improved Self Lowering and Adjusting Metallic or other Fire Proof
Material Shutters for Prosceniums of Theatres and Music Halls.
1. FREDERIC BARNETT of 106 Queen Victoria Street City London, Civil Engineer 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:
That as fires in Theatres nearly always commence on their stages it is of the utmost
importance that they should be there localized as long as possible both with the object
of reassuring the audience to induce a calm retreat and at the same time to improve
the chance of saving the auditorium. To attain this end I establish above and just
behind the Proscenium shutters of fire proof iron plates or other suitable material
wide enough to extend each side to the walls of the building in such cases as the
Prosceniums are not built in brick or other fire resisting material but when the last
exists the shutters would just exceed the width of the Proscenium and for preference
should work in the grooves of 1 iron rolled joists established on solid foundations on
the basement ground extending vertically sealed at right angles in the masonry on
each side up to and above the Proscenium to such height as will enable them thoroughly
to support the pulleys and bearings charged with the whole weight of the shutters or
curtains. The brackets in which the pulleys are to work on their bearings are also to
be sealed in the masonry of the Proscenium Wall.
The endless chains A to which are connected the shutters or curtains will be
connected on opposite sides of the chain on the one side the upper half shutter and
on the other side the lower half of the shutter or curtain B. The endless chains will
work in two pullies above C and two pulleys below the stage on each side of the
Proscenium.

page_text: s of the
grooves.
The two lower pulleys D for choice to be united at the extreme ends of a shaft
supported and retained in its place on bearings E established on plummers blocks well
held down to the lowest ground beneath the Stage. In the indurated
two pulleys the endless chains F will work being well gripped revolving simultaneously
by means of the connecting shaft G either to lower or raise the fire proof shutters and
the shaft in its turn will be governed in most cases by diagonally working tooth
wheels H which by vertical rods will pass through on to the stage floor I terminating
in a hand working winch which will assist in raising the upper and lowering the lower
shutter when so required.
The same being set in motion by the preponderating weight of the upper half falling
by its own gravity and at the same time raising the lower and lighter half until the
two meet half way in close contact without noise.
When required to restore the upper and lower halves to their respective berths J
there being but a slight difference in their weights It will only be that difference to
raise as the equal weights balance each other and this can be readily effected by means
of the small winch on the Stage, but should the fire in that immediate locality prevent
access to raise the brakes governing the winch I shall arrange either from an outer
wall or elsewhere to do so.
The same principle I arrange to windows and doors, with reference to windows
when there is sufficient space above and below, 1 adopt as nearly as possible the same
modus operandi as that above described for the theatrical shutters, the material to be
employed will be of much slighter substance, but when the spaces above and below
are insufficient, I equally effect the same purpose by gravity, to obtain an automatic
closing, in either case for doors or windows when the action is to be horizontal the
half shutters will when out of work be hidden by panels on each side, for choice on one
side where by pressing a knob (or otherwise) K the two opposite shutters L will be set
in motion and finally meet and lock each other rapidly. On the upper parts of each
shutter will be two or more grooved wheels M to work on two bars of iron N or other
metal of sufficient strength, one shutter on each bar (on the opposite bars) but so
arranged that they will meet and lock from the inside these two shutters are to be
connected by one chain extending O from a small winch K behind or before the panel
to a horizontal wheel P fixed so that the chain coming from the winch will turn round
it and return also attached to the opposite shutter, and when quitting the second
shutter the chain will in the panel pass over a grooved vertical wheel sustaining
from its extremity a weight R sufficiently heavy that when released by the winch it
will draw the first shutter forward in one direction and the other shutter in the opposite
direction till the two meet and lock.
When the shutters acting for doors or windows are meant to be opened they will be
unlocked from the inside of the room, and drawn back to their berths by a crank key
(like such as are used for winding large clocks) acting on the winch for which effect
only a trifling force will be required.
The bottoms of the two shutters or doors will move in slots or run on wheels
on bars.
These horizontal shutters when it may be inconvenient to close them in the same
room will have communications from other parts of the buildings to liberate the brakes
or cogs and enable the pendant weight to fall and in its traction automatically to close
the shutters at once, presenting the dual protection against fires and burglars.
I may explain the shutters acting horizontally are in their position vertical.
Having now particularly described and ascertained the nature of the said inven-
tion and in what inanner it is performed I declare that what I claim is
1° By suspending the fire-proof shutters in Theatres and Music Halls on endless
chains.
2° Thereby the automatic closing the upper and lower shutters, whether the lower
be made in one or more shutters.
3° The ability to employ a small winch to restore when in use the upper shutter to
its berth above the Proscenium and the lower shutter below the stage the only power

page_text: required being the difference in weight an excess of one hundred weight or more in the
upper shutter over that of the lower and an addition to augment the celerity in closing
according to requirement.
4° The application of the same modus operandi to windows when the spaces above
and below are sufficiently large; but if such be not so-then by the employment both
for windows and doors of a similar principle but by a partly horizontal and vertical
endless chain 0. 0. O. with balance weight R-Plate 11.
5° That by reason of a fire rendering it inexpedient in Theatres, Rooms, or other
Buildings, to approach the winches by which to close the shutters, shall arrange
chains or other communications to liberate the cogs or brakes that otherwise retain the
shutters out of action.
6° That by couplings in the endless chains tension or slack can be corrected.
7° That the speed in closing can be regulated as it may be required by adding
weight to either the upper or lower shutters.