Year: 1888

page_text: ContractID, an
I, PAOLO PORTA of 16 Via San Zeno, Milan in the Kingdom of Italy, 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:—
•
The object of this invention is to provide a ladder which is capable of being divided
into a number of small sections for portability and convenience of manipulation in
erecting the same in combination with a suitable carriage for transportation from
place to place and a means for raising the ladder quickly and easily and for
adjusting the same when raised to any desired angle. Such a ladder is suitable for
fire brigades for escapes and scaling ladders, contractors' work of all kinds and military
purposes.
And in order that my invention may be more fully understood I will proceed to
describe the same with reference to the accompanying sheets of drawings in which
Figure 1 sheet 1 shews side elevation of a ladder constracted according to my
invention raised ready for use. Figure 2 sheet 1 end elevation of same viewed from
the back. Figure 3 sheet 2 shews same ladder packed for transport. Figures 4
and 5 sheet 2 shew details of joint. Figures 6 and 7 key or cotter for securing the
same. Figure 8 sheet -2 shews a small ladder mounted on a two wheeled cart or
truck suitable for transport by hand. The same letters denote the same parts in all
the figures.
According to this invention I make the ladder in sections a b c d e either end of
each section being provided with strong metal straps ff these straps are recessed to
make with the straps of the next section a half-lap joint the key or cotter g (Figures 6
and 7 shew this on an enlarged scale) forming also a rung of the ladder, passes
through the spaces / left between the end of the side picces and the strapsf securing
the sections longitudinally. In order to prevent flexure of the ladder I brace or truss
the same with tie rods i and j and struts k to each section, these tie rods are slipped
on to the pins and m and secured by cotters passing through the said pins.
The bottom section a of the ladder is formed into a bell crank lever the short arm
of which is provided with a roller n over which passes a chain o one end of which is

page_text: 9
anchored to the carriage at p and the other end is attached to the winding barrel
which is rotated by means of the spur wheel and pinions actuated by the crank
handles and the section a is supported on trunnions v turning in bearings won
the carriage x. The carriage is provided with balance weights z supported by
bars A sliding on friction rollers B, these weights are run out when the ladder is
horizontal and run in as the ladder is raised to the perpendicular. I also provide a
winding barrel C at the fore part of the carriage to which a rope may be attached for
hoisting buckets, hose, and other articles to the men working on the ladder the горе
being rove through a suitable snatch block fastened to a rung of the ladder. For
raising very long or heavy ladders I provide a winding barrel E actuated by wheel F
and pinion G attached to the balance weights and a guide roller H attached to two
uprights I, (shewn removed in Fig. 2.) as shewn, a rope being fastened to the
winding barrel E and to a convenient point along the ladder. The winding arrange-
ments may be made double or treble purchase or even more powerful if desired
and when raising very long ladders the extra rope is used in conjunction with the
ordinary winding gear, the balance weights being trussed in the position shown in
dotted lines at Figure 3 for this purpose. D is a guide roller.
Figure 8 sheet 2 shews a ladder made according to my invention designed to be
manipulated by one man and is mounted on a two wheeled truck and adapted to be
raised in the same manner as the others. The balance weights N are loose and are
hooked on to the lever O which lever is attached to the carriage by the pin R and
folds along the side of the carriage when out of use the balance weights being hung
on the hook P. I provide the carriage with sliding legs K' in the front of the
carriage to steady the same when the ladder is in use, the said legs being adjusted
to suit the ground upon which the carriage is standing and secured in their places
by pins passing through them. To prepare the ladder for use the balance weights
are run out and the bottom section lowered on to the stop K and the sections
added one by one, the tie rods of one section being coupled up before the next
section is added, the keys or cotters put in their places and the ladder raised to the
desired angle by means of the winch handles t and u, a ratchet and pawl L M. holding
the ladder in any desired position.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is :-
1st. In a portable sectional ladder the method of securing the sections together
substantially as described.
2nd. In a portable sectional ladder the means for raising the same in combination
with a travelling carriage substantially as described..
3rd. In a portable sectional ladder the means for balancing the weight of the ladder
at any angle substantially as described.
4th. The improved sectional ladder substantially as described and shewn in the
drawings.
Dated this Thirty-first day of May 1888.
BROWNE & Co.,
Agents for the Applicant.