IMPROVEMENTS IN EXTENSIBLE FIRE ESCAPE LADDERS
Year: 1883

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and
W Clark of 53 Chancery Lane in the County of Middlesex Fellow of the
Institute of Patent Agents for an Invention of IMPROVEMENTS IN EXTENSIBLE
FIRE ESCAPE LADDERS communicated to him from abroad by Daniel D Hayes
of San Francisco, in the County of San Francisco and State of California,
United States of America
•
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 14th February 1883.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex Fellow of the Institute of Patent Agents
"IMPROVEMENTS IN EXTENSIBLE FIRE ESCAPE LADDERS [communicated to him
from abroad by Daniel D Hayes of San Francisco, in the County of San Francisco
and State of California, United States of America]
"
The object of this Invention is to facilitate the transporting and operating of
fire escape extension ladders.
The Invention consists in a fire escape extension ladder constructed with a torn
table connecting the ladder with its truck, so that the direction of the ladder can
be changed without moving the truck
The main section is pivoted on a horizontal shaft in standards rising from the
turntable, and has downwardly extending brackets attached carrying a pivoted nut
to receive a screw swivelled to a block pivoted in supports fixed on the turn table,
whereby the ladder can be readily raised and lowered.
The extension section is raised by means of a pair of endless chains which pass
up one side of and down the other side of the main section and run on guide rollers
at the upper end and on chain wheels on a cross shaft at the lower end of the main
section the shaft having a winch handle at either end whereby the ladder can be
readily extended and contracted.

page_text: The parts of the ladder are kept in place upon each other by keepers attached to
the extension section and having a roller taking under the side bars of the main
section and by keepers attached to the main section and overlapping the side bars
of the extension.
The extension section is supported in place by a pawl pivoted to its lower end
held up by a stop pin, and engaging by a recess in the pawl with a round of the
main section.
With this construction the ladder can be readily raised to any required angle,
can be easily extended to the required length and can then be turned to bring its
upper end into any required position, so that it will not be necessary to adjust the
truck into a particular position to allow the upper end of the ladder to be brought
into contact with any given place, as for instance with a window of a building.
With this construction also the position and direction of the ladder can be
changed without its being necessary to move the truck.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Great Seal Patent Office on the
14th August 1883.
ALEXANDER MELVILLE CLARK, of the firm of A M and W Clark, of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents
IMPROVEMENTS IN EXTENSIBLE FIRE-ESCAPE- LADDERS a communication to me from
abroad by Daniel D Hayes, of San Francisco in the County of San Francisco and
State of California, United States of America
The object of this Invention is to facilitate the transporting and operating of fire
escape extension ladders.
The Invention consists in a fire escape extension ladder constructed with a turn-
table connecting the ladder with its truck so that the direction of the ladder can
be changed without moving the truck. The main section is pivoted on a horizontal
shaft in standards rising from the turntable, and has downwardly extending
brackets attached carrying a pivoted nut to receive a screw swivelled to a block
pivoted in supports attached to the turntable whereby the ladder can be readily
raised and lowered. The extension section is raised by means of a pair of endless
chains which pass up one side of and down the other side of the main section and
run on guide rollers at the upper end and on chain wheels on a cross shaft at the
lower end of the main section, the shaft having a winch handle at either end
whereby the ladder can be readily extended and contracted. The parts of the
ladder are kept in place upon each other by keepers attached to the extension
section and having a roller taking under the side bars of the main section, and by
keepers attached to the main section and overlapping the side bars of the extension.
The extension section is supported in place by a pawl pivoted to its lower end held
up by a stop pin and engaging by a recess in the pawl with a round of the main
section:
The Invention is illustrated in the accompanying drawings in which similar
letters of reference indicato corresponding parts in all the figures.
Figure 1 is a side elevation partly in section of the improvement shown in
position for transportation. Figure 2 is a side elevation partly in section of the
same elevated, and partly extended. Figure 3 is a plan view of the rear part of the
same, parts being broken away. Figure 4 is a plan view of a part of the same
showing the pawl.
A are the rear wheels, to the axle B of which is attached the rear part of the
platform or frame C. The forward part of the frame C is made with a downward
offset and is attached to the bolster D of the forward axle E so that the forward
wheels F can pass in beneath the frame C in turning. To the forward part of the
frame C are attached standards G connected at their upper ends by a cross bar H
to form a support for the ladder when being taken from place to place. To the
rear part of the frame C is attached the stationary part I of a turntable which bas
an outwardly projecting flange J formed around its upper edge to fit into a groove
in the inner side of the downwardly projecting flange K. formed upon the lower
side of the outer edge of the movable part L of the turntable so as to pivot the
said movable part to, and keep it in place upon, the stationary part I. To the
opposite sides of the movable part L of the turn table are attached two V shaped
brackets M, to the upper ends of which is attached a shaft N which passes through
lugs attached to the main section P of the ladder at a little distance from its
lower end so as to support the ladder and hinge it to the turntable. To the lower

page_text: =
part of the main ladder P at points about equally distant from the shaft N are
attached shaped brackets Q, to and between the lower ends of which is pivoted
a nut R through which passes a screw S. The rear end of the screw S is swivelled
to a bearing block T which is pivoted to and between supports U attached to the
rear side of the movable part L of the turntable. The rear end of the swivelled 5
screw S is squared to adapt it to receive a winch handle by means of which said
screw is turned.
With this construction, when the screw S is turned back, the nut R is forced
forward which turns the ladder upon its hinge and raises its forward end to any
desired height, the pivots of the nut R and swivel block T giving the necessary 1
freedom of movement as the rear end of the ladder P moves through the arc of a
circle.
Upon the main section P of the ladder is placed the extension section V which
is kept in place by the keepers WX. The keepers W are attached to the outer
sides of the lower end of the extension ladder V and their ends cross the side bars 1
of the ladder P and have small rollers Y pivoted to them which rest against the
lower edges of the side bars of the main section P so that the two sections will
move easily upon each other. The keepers X overlap the upper side of the
ladder V and their ends are bent downward, cross the side bars of the extension
ladder V, and are attached to the side bars of the main ladder P so that the said 2
keepers will keep the extension ladder in place. To the lower part of the extension
ladder V are attached chains Z which pass around a guide roller a or pulleys pivoted
to the upper end of the ladder P. The chains Z also pass around chain wheels b
attached to a shaft which revolves in bearings at the lower end of the main
ladder P. One or both ends of the shafte project and to them are attached cranks d 2
by means of which the said shaft is turned to raise and lower the oxtension.
ladder V. To the lower end of the extension ladder V is pivoted a pawl c the
lower end of which is recessed to engage with a round of the main ladder P and
hold the said extension ladder securely in any position into which it may be
adjusted.
The forward side of the pawle is recessed to receive a pin f attached to the
lower end of the ladder V to support the said pawls in such a position that its
recessed lower end will engage with the rounds of the ladder P and hold the
extension ladder V securely in any position into which it may be adjusted. The
rear side of the pawl e is recessed to receive a round of the ladder V or a pin g
attached to the lower part of the said ladder and support the pawle when turned
back, as for instance, when the extension ladder is to be lowered.
With this construction the ladder can be readily raised to any required angle,
can be easily extended to the required length and can then be turned to bring its
upper end into any required position so that it will not be necessary to adjust the 4
truck into a particular position to allow the upper end of the ladder to be brought
into contact with any given place, as for instance, with a window of a building.
With this construction also the position and direction of the ladder can be
changed without its being necessary to move the truck.
Having described the nature of the said Invention and the manner of
performing the same, I declare that what I claim as the Invention to be protected
by the hereinbefore in part recited Letters Patent is.
1 A fire escape extension ladder constructed substantially as herein shown and
described and consisting of the following elements, viz-a mechanism for turning
the ladder, a mechanism for raising and lowering the ladder, and a mechanism for
extending and contracting the ladder, as set forth.
2nd In a fire escape extension ladder, the combination with the truck frame C
and the ladder P supporting brackets M of the turntable I L substantially as
herein shown and described, whereby the direction of the ladder can be changed
without moving the truck, as set forth.
3rd In a fire escape extension ladder the combination with the turn table I L

page_text: and the hinged ladder P, of the brackets Q, the pivoted nut R, the swivelled
screw S, and the pivoted swivel block T, substantially as herein shown and
described whereby the ladder can be readily raised and lowered, as set forth.
4th In a fire escape extension ladder, the combination with the sections P V of
the ladder, of the chains Z, the guide roller a, and the chain wheels and crank
shaft b c substantially as herein shown and described whereby the ladder can be
readily extended and contracted, as set forth.
5th In a fire escape extension ladder, the combination with the sections P V of
the ladder, of the keepers W having rollers Y, and the keepers X, substantially as
herein shown and described, whereby the said parts will be kept in place upon each
other, as set forth.
6th In a fire escape extension ladder the combination with the extension part V
of the ladder, of the pawl e having recessed forward end, and the stop pin f sub-
stantially as berein shown and described, whereby the said pawl will engage
automatically with the rounds of the main ladder and support the extension ladder
in place, as set forth.
In Witness whereof I the said Alexander Melville Clark have hereunto set my
hand and seal this thirteenth day of August, A.D. 1883.
r AT D17