IMPROVEMENTS IN PORTABLE LADDER- APPARATUS CHIEFLY DESIGNED TO SERVE AS A FIRE-ESCAPE
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 29th December 1883. Communicated
to him from abroad by Enrico Canziani, of Milan, in the Kingdom of Italy.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, & Co,. Patent Agents,
Southampton Buildings, London "IMPROVEMENTS IN PORTABLE LADDER-
APPARATUS CHIEFLY DESIGNED TO SERVE AS A FIRE-ESCAPE" [a communication
to him from abroad by Enrico Canziani, of Milan, in the Kingdom of Italy.]
This Invention relates to portable ladder apparatus chiefly designed for use as a
fire escape.
A fire escape or portable ladder constructed according to this Invention comprises
two parts, a carriage supporting the escape or ladder, and the escape or ladder itself
which is composed of several sections. The carriage, which may be provided with
two or four wheels, is strongly built and may be drawn either by horses or by men.
The sections of ladders carried upon this carriage have about the same length as
the latter and are placed on the top of one another in the order in which they
have to be connected. Upon each side of the carriage, and also in the same order
as above, are placed tie-bars which join the various sections together.
The mechanism required to erect the said fire escape or movable ladder is joined
to the carriage which also carries the apparatus necessary for the erection of the
said fire escape or movable ladder. This fire escape or ladder proper is composed
partly as above stated of a number of sections varying according to the height
which it is required to reach. The lower sections of the ladder are the strongest
the upper sections gradually decreasing in strength towards the top, so that the
last and highest is also the lightest. The first section of the ladder, that is to say,
the lowest one is formed in the shape of a bent lever, the two arms of which are
firmly tied by means of iron bars and rotate upon a shaft situated close to the apex
of the angle formed by these two arms. The other sections are joined to the first
section when in a horizontal position, thus assuming the form of a bridge.
Upon the shortest arm of the said lever or tail of the escape is applied the power
required to cause the longer arm, that is to say the Escape or ladder, to be raised so
as to obtain an equilibrium between the two arms whatever may be the inclination
required for the said escape or ladder from a horizontal line to a nearly vertical
line.

page_text: The power required is supplied by men working the cranks, actuating shafts
carrying pinions which gear with toothed wheels integral with a pulley around
which are coiled cords or chains which transmit motion to the tail of the escape or
short arm of the lever after having passed over another pulley fixed to the frame
of the carriage. The different sections are numbered and carry at their extremities
and on each side, iron cups and sockets which fit into one another and are secured
by a wooden bar. Two iron rods are fixed to each ladder perpendicularly to its
side bars. The steps or rounds fixed to the said side bars are also made of wood.
In order to erect the escape, the various sections of ladders must be first arranged
upon the ground or pavement, one next to the other in their proper progressive
order and in the direction of the axis of the carriage. These varions sections are
joined by means of four tie bars or movable rods for each section, two of which
parallel to the side bars of the said sections, join the upper extremities of the iron
rods, whereas the other two connect diagonally the upper part of the rods of one
of the sections to the side bars of the other by means of small iron pins. At the
same time, the wooden cross bars are passed through the sockets and caps which fit
one another. Each wooden cross bar thus occupies the place and serves as one of
the steps or rounds.
As soon as the various sections of ladder are joined together in a horizontal
position the escape is raised gradually from this position to nearly a vertical one
according to the inclination desired, in order to attain the point which it is intended
to reach.
The equilibrium of these escapes or ladders, whether joined horizontally or
raised at various inclinations, is obtained by means of counterweights placed upon
the extremity of the carriage and in a contrary direction to that of the escape,
which counterweights may be made to slide between guides placed in any suitable
position according to the degree of inclination required.
The escape once erected must not have any other resting point apart from the
carriage.
The escapes or ladders mounted upon a carriage provided with two wheels differ
from those mounted upon a carriage having four wheels inasmuch as in the former
the various sections of ladders are unloaded at the back of the carriage, whereas
in the latter the sections are unloaded in front of the carriage close to the shaft.
The first serves for heights up to fifteen metres and the others for greater heights.