A NEW OR IMPROVED FIRE ESCAPE TOWER OR STAIRCASE
Year: 1885

page_text: .I, WILLIAM PHILLIPS THOMPSON, Fel. Inst. P.A of the Agency for Foreign Patent
Solicitors 6, Lord Street, Liverpool in the County of Lancaster and 323 High
Holborn in the County of Middlesex, Civil Engineer do hereby declare the nature
of the said invention for A NEW OR IMPROVED FIRE ESCAPE TOWER OR STAIRCASE
(a communication from abroad by Christopher Clarke of Northampton, county of
Hampshire, and state of Massachusetts, United States of America, inventor), and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to improvements in Fire Escape Towers, having for their
object the provision of passage ways in the same tower which cannot be obstructed
by the jamming of separate queues or crowds at the landings of different floors
communicating with the tower and which cannot become filled with smoke from a
fire in any part of the building of which it forms part and consists in the arrange-
ment around a common axis of two or more spiral passage ways formed to be. each
completely isolated from the others for its whole length.
The invention is fully illustrated in the accompanying drawings in which
Figure 1 is an elevation in partial section of a tower having my improvements
and
Figure 2 is an elevation in partial section of a modification of the same.
A is the wall of a tower which may form part also of the main wall of the
building or may be that of a detached tower.
D D are door-ways giving access to the tower from the first and second floors
respectively of a building H
B¹ is a spiral stair-way leading from the door-way D¹ to the exit C¹ at the base
of the tower.
B is a spiral stair-way leading from the door way D upon the first floor of the
building to the exit C at the base of the tower.
E is an axis common to both ways B B¹.
To more clearly distinguish the two ways the one B is shown with a smooth
surface or treadway, and it is immaterial to the invention what surface is provided
for this purpose.

page_text: It will be seen that two columns of people descending the stairways B B¹ will be
completely shut off one from the other and that people escaping from the building
cannot be crushed in converging masses.
So that in theatres, school-houses, and other crowded buildings, one great danger
incident to fires or panics may be avoided.
In school-houses or other places where the sexes are divided the stair-ways B B¹
may lead from the same floor, by having separate entrances provided through the
wall A, by means of which the strong are prevented from trampling the weak.
In Figure 1, in order to more clearly show the invention railings HH' are placed
at the landings at the head of ways B B¹ but in practice if the tower is partially or
entirely enclosed in the building so that smoke could penetrate it through the
doors leading thereto, for said railings are substituted solid partitions joined to the
surfaces of axis E and bottom of stair-way above by means of which the ways B B¹
are so isolated that smoke pouring into the tower from any lower floor could not
reach the other way, nor could smoke from the upper floor have access to the way
leading from the lower.
In Figure 2. The ways B B¹ are shown around a common axis E but separated
by a wall F so that one way instead of being parallel to and below the other is
concentric thereto which form of construction enables the pitch of the two ways to
be varied if desired, to bring the exit of the outer to any point in the circumference
of the tower, or to adapt it to a difference of rise in the two stories.
Both passage ways as shown in Figure 2 are completely isolated the inner one is
lighted by windows g those within the outer wall A of the tower being placed
opposite the ones h in the wall A, and these windows are formed of thick heavy
glass not easily broken or influenced by heat.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is
1st. The within described improvements in Fire Escape Towers consisting of the
arrangement within a tower and around a common axis of two or more spiral
passage-ways having separate entrances and exits and each constructed to have no
intermediate passage way leading thereto from beginning to end and to each have
no possibility of exit therefrom from end to end, for the purpose as set forth.
2nd. In a Fire Escape Tower the combination and arrangement within a tower
and around a common axis of two or more spiral passage ways adapted to be each
inaccessible from the others and to be each smoke tight and isolated from the others
for the purpose as set forth.