Improvements in Portable Fire Escapes and Extensible Ladders.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Portable Fire Escapes and Extensible Ladders.
I, THOMAS PATRIck Purcell, of Chatham Row, Dublin, Chief Superintendent
of Fire Brigade, do hereby declare the nature of this invention to be as follows:-
My invention relates to the improvement in construction of portable extension
ladders capable of being conveniently used as fire escapes and is applicable to
other purposes.
The object of this invention is to provide a set of extension ladders, which,
while capable of reaching to a considerable height, are so mounted on a vehicle
as to have the centre of gravity low, and may be rapidly conveyed by horses or
other power through ordinary thoroughfares, under wires, bridges or other struc-
tures projecting overhead; immediately raised from the horizontal position to
any angle up to the vertical, swung around to any point within a complete circle,
extended to reach the full height for which the ladders are constructed and used
at once without requiring any adjustment of parts, or extraneous support to the
ladders.
By my invention it is possible to raise and slue the ladder into any position,
and to raise, lower, or alter the angle of the ladders while in such position by
the operator from the ground; the several movements are performed either alter-
nately or simultaneously as desired by means of one crank handle with double
ratchet motion substantially as described.
All the operations including extension to full height may be performed by one
man unaided.
Means
In carrying out my invention I provide a series of trussed ladders, fitted teles-
copically, and pivot them at the lower end in a turn-table capable of being re-
volved by means of gearing on its base, and mount the whole with a suitable
four wheeled truck or other vehicle, upon which the ladders lie in an oblique or
horizontal position while being moved to the place where required for use.
for raising the ladders to the vertical position by a flexible wire rope roved
through shrouded pulleys at both sides in the outer end of a rocking frame pivoted
in advance of the ladders, and led over pulleys on tubular or wrought metal
staunchions also mounted on the turn-table, to the winding drums on a winch
carried in its base.
One part of my invention consists in the methods of construction of a geared
turn-table as applied to fire escapes and extension ladders.
A base or wheelrace of wood, wrought metal, steel or bronze, or combination
of these materials, built up of a flanged section, truly formed on the top surface,
and with flanged legs or other suitable means of support for attaching to framing
of the truck, and having webbed arms carrying a bored centre boss for upright
turned spindle and a bearing for the first motion shaft, on the base thus formed
will revolve a metal or steel wheel carrying the pivotal bearing for ladders, and a
winding drum for raising them to the vertical position, the outer portion of this
wheel is formed with toothed gear, the inner part being truly faced, bored and

page_text: turned to fit the wheel base. An annular ring preferrably of wrought iron clamped
to the wheel and extending under the flange on race, while allowing the wheel
with its superimposed ladders to revolve freely prevents any lifting of the wheel,
and distributes the strains due to the ladders over the wheel base.
Instead of the annular ring I may use a series of hardened steel flanged rollers
fixed by studs to the wheel, and bearing against and beneath the flange on race.
The raising motion consists of an upright spindle with nuts and washers fixed
rigidly in the lower boss, which receives a loose double bevil pinion capable of
being freely rotated on said upright spindle, the bottom side gearing with a similar
but single pinion keyed fast on the end of first motion shaft, while the top side
gears with a bevil wheel proportioned to the power required, rigidly keyed on to
the winding drum shaft, this latter shaft is provided with a pair of drums of a
conical or fuzee pattern, with a spiral groove cut right and left hand respectively in
their peripheries, on which the lifting rope from the raising frame is coiled at a
varying speed, or preferably a pair of metallic reels may be used for the same pur-
pose, the flanges on the reels to be deep and placed so close that the rope must
coil upon itself and go on increasing the diameter at each portion of the revolution
as the weight of the ladders decreases when rising.
A raising frame hinged or pivoted in brackets attached to the turn table in
advance of the ladder pivots, extending some convenient length at both sides and
beneath the main ladder is provided at the extreme outer end with a suitable
distance piece, carrying two pulleys for the wire lifting rope properly housed in
shroudings, two rollers are also carried on the distance piece which engaje with
the sides of main ladder when the winch is operated by a crank handle more
particularly described hereafter, the frame having a toggle or frictional wedge
action gradually traverses its rollers down the guide path on the back or under-
side of ladder, raising and forming a support to same at every part of its motion.
A ratchet and pall on the first motion shaft retains the ladders at any desired
angle.
The slueing motion is performed by means of a bevil pinion gearing into the
under side of large wheel or turn table, on the back of the pinion and keyed
solid with it on same shaft is a spur wheel which gears into a pinion with a long
sleeve carried in a bracket bearing beneath the wheel, and enclosing the first
notion shaft for the raising gear; both outer ends of sleeve and first motion shaft
are solidly flanged and slotted to receive the spring catches in the operating crank
handle.
The crank handle has a stock of forged steel or other metal, bored out from
end to end for the piston catches, bored across centre boss to go over the swelled
end of the first motion shaft, and recessed on both sides to receive the slotted
flanges, sliding piston satches with spiral springs within the stock engage with
slots in flanges on opposite sides of the boss, and are disengaged by a small lever
working on a spirally raised track with stop notch on heads of stock or by a cam
action on the levers.
Another part of my invention relates to the means by which the strain is
equalized on every part of the double lifting ropes, used both for raising and
extending the ladders. I accomplish this by fixing near the bottom of each sliding
ladder a tubular round or tread, provided with enlarged metallic ends of quadrant
shape, in which a curved circular hole is cored or otherwise formed, the curvature
to be struck with a radius from a centre equidistant from the side of the ladder
and centre of tread, the lifting rope passed through the curved passage and
hollow tread is carried over the lifting pullies to the winding drums, or I mount
in lugs attached to the treads or to the feet of lifting pulley staunchions suitable
grooved sheaves through which the ropes are led.
Another part of my said invention is the combination of diagonal bracing with
the supports for extending pulleys in the top portions of the main and first sliding
ladders, and of an improved form of mounting for the heads of ladders, combining
and consisting of a metallic socket embracing the top of each wood side, carrying

page_text: a socket for the better attachment of trussing members, a clip for the sliding
ladder, and a lug in which the top round carrying suitable guide rollers is secured.
In connection with the aforesaid invention as described I also employ a method
of combining and carrying within the truck frame, one single trussed ladder,
and one pair of light trussed extension ladders, so placed as to be clear of the
main ladder when travelling or working, and capable of being easily withdrawn
and used independently for any purpose as required, or of being spliced on to the
top of main sliding ladder, by spring catches and adding such additional length
thereto.
I also provide ladders in connection with a turn-table with an alternative
method of raising and slueing, and use for this purpose a tubular braced, wrought
metal or wood lever, fixed rigidly to the heel, and with stays to the sides of main
ladder, the outer portion of the lever is hinged and folds over the standing part
when travelling, and is provided with a pair of spring catches which automatically
fixes the lever when pulled over into position.
Dated this Third day of June 1898.
I, THOMAS PATRICK PURCELL, of Chatham Row, Dublin, Chief Superintendent
of Fire Brigade, 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;-
My invention relates to improvements in portable extensible ladders for fire
escapes and other purposes.
The object of this invention is to provide a set of extension ladders, which,
while capable of reaching to a considerable height, are so mounted on a vehicle
as to have the centre of gravity low, and may be rapidly conveyed by horses or
other power through ordinary thoroughfares, under wires bridges or other struc-
tures projecting overhead; they may be immediately raised from the horizontal
position to any angle up to the vertical, swung around to any point within a com-
plete circle, extended to reach the full height for which the ladders are constructed,
and used at once without requiring any adjustment of parts, or extraneous support
to the ladders.
By my invention it is possible to raise and slue the ladders into any position,
and to raise, lower, or alter the angle of the ladders, while in such position by
the operator from the ground; the several movements are performed either alter-
nately or simultaneously as desired by means of one crank handle with double
locking motion substantially as described.
All the operations including extension to full height may be performed by one
man unaided.
In the accompanying two sheets of drawings I have shewn how my said invention
may be conveniently and advantageously carried into practice. The same letters
refer to similar parts on different drawings. Figure 1, Sheet 1, shews a side
elevation of the general arrangement of the fire escape when in its horizontal or
travelling position, the dotted lines indicate the position of ladders when raised
for use, it is to be noted that although but one side is shewn generally the references
to that side will equally apply to the other, both being practically alike.
Figure 2, Sheet 1, is a plan of escape partly in horizontal section.
Figure 3, Sheet 1, is a front elevation shewing the ladder supports, double
driving seats, and hose box.

page_text: Figure 4, 5, Sheet 1, are different views shewing details of construction in
plan and section.
Figure 6, Sheet 2, is a back elevation partly in vertical section.
Figure 7, 8, Sheet 2, shew different views of the ladder with my improved
metallic cap, guide rollers and diagonal bracing. All the figures to 8 being to a
uniform small scale.
Figure 9, Sheet 2, to a scale twice as large as Sheet 1, is a sectional view of
the turntable with winding reels for raising the ladders, and gearing for operating
them, also gearing for revolving the table and ladders.
Figure 10, Sheet 2, to the larger scale is a plan of the turntable with winding
reels on shaft, and two brackets for one side of the raising attachments.
Figure 11, 12, 13, Sheet 2, shew details of the brackets.
Figure 14, 15, Sheet 2, to a scale four times as large as Sheet 1, shew the
details partly in section of my improved arrangement for the double action crank
handle which operates the gearing.
Figure 16, 17 Sheet 2, to the largest scale, partly in section shew my improved
arrangement of hollow tread for equalizing the strain on double lifting ropes for
ladders.
Figure 18, Sheet 2, to the largest scale shew the details of my improved form
of metal cap with guide rollers and clips as applied to the top on a set of sliding
ladders.
In carrying out my invention I use a truck or trolly mounted on four road
wheels for travelling, with springs, axles and locking forecarriage as more par-
ticularly indicated by the drawings Fig. 1, 2, 3, 6, near the rear of truck and
between the side frames A which are preferably of a chanelled section of steel.
I securely fix a framing or casting of steel or other metal A 1, having a flanged
top part A 2, forming the race upon which the turn-table B revolves. The turn-
table B is a bronze or steel casting with a geared ring on the outer part of the
underside of rim, it is turned to fit accurately over, and revolve on the flanged
part A2, and is securely held in position and prevented from lifting by a wrot
iron annular ring B2 clamped beneath the flange A 2 by bolts B3 passing through
bosses formed at the junction of arms with rim of turn-table B. Or I use a
series of hardened metal rollers, working on stud bolts beneath the flange. The
turn-table is further secured by the turned steel upright pin A3, which is secured
in the centre boss of wheel base A 4, passes through the centre boss B4 in the
arms of turn-table and provided with nut A5 on top.
Motion is communicated to the turn-table by means of the bevil pinion C
gearing into the teeth on underside of large wheel B on the back of pinion C
and keyed solid with it on shaft C5, is a spur wheel C2, which gears into a spur
pinion C3. This pinion has a long sleeve carried in the bottom bearing of
bracket C4, and a solid flange C6, on outer end slotted to receive the sliding
catch H2 in the improved crank handle H, it is also bored through and forms a
bearing for the first motion shaft D.
I provide a series of trussed ladders consisting of one main ladder L pivotted
in brackets D7 attached to the turn-table, with two or more sliding ladders L1, L2,
fitted telescopically and capable of extension by means of a wire rope L3 carried
through my improved form of hollow tread with cored quadrant ends L4 fixed
near the base of the sliding ladder L1, thence over the shrouded pulleys L5, in
head bracing L 6, of main ladder, and down to the drums on a geared winch L7,
fixed on the back of main ladder near its base. The additional sliding ladders
are extended by similar ropes passed over the pulleys L5 in the ladder beneath and
secured to the sides of main ladder in the case of the third, and to first sliding
ladder in the case of the fourth.
By this system I equalize the strain on every part of the rope and ensure the
ladders extending in a right line.
For the head of every ladder I provide a pair of light metallic caps M com-
pletely encasing the wood sides, with sockets M1 to receive the ladder trusses, a

page_text: tubular steel top round M 2 with solid ends carrying a pair of guide rollers M3,
and a steel clip for sliding ladders M 4, and in every ladder except the top one, 1
fix tubular diagonal bracing LG, in that portion covered by the lap or splice
when the ladders are extended.
When travelling the ladders lie in an oblique or nearly horizontal position
between the two drivers scats S, and the head is supported by bearers SI, and
brackets S 2.
I provide means for raising the ladders into the vertical position or to any
lesser angle when required for use, in the following manner. In brackets R
attached to the turn-table in advance of ladders. I hinge a swinging frame,
whose tubular sides R 1 extending longitudinally beside and beneath the ladders
are furnished at their outer ends with two shrouded sheaves R2, and a cross bar
or distance piece connecting them, with bearings upon which revolve flanged
friction rollers R3, these rollers are kept in contact with the underside of the
main ladder by the roller paths R 4; springing from the brackets R and R 5 on
turntable are tubular stanchions RG and R7 supporting a shrouded sheave R8
on both sides of the ladder A wire lifting rope R 11 is roved beneath the equaliz-
ing sheaves R9, up through the tubular stanchions R7 thence through a curved
passage R 10 in shrouding, over the sheaves R2 in ends of swinging frame, back
over the shrouded sheaves RS on top of the stanchions and led down to the winding
reels DG on shaft D5, hereinafter described.
The motive power for lifting is communicated to the reels D6 by means of my
improved form of crank handle H at rear of escape, more particularly described.
The outer ends of first motion shaft D has a solid slotted Hange 1) 1 with which
sliding catch H1 in stock of handle engages, keyed on the inner end of shaft is
a mitre pinion D2, which gears with a mitre cast solid with bevil pinion D3
this double pinion is loose on the upright pin A 3, and gears with the bevil
wheel D4, this latter is fixed on the reel shaft 15, running in bearings in the
brackets 7 and carries the two winding reels D6, which thus receive their
motion when the handle H is turned. A ratchet DS, on first motion shaft and
pall D9 automatically retains the ladders in any desired position.
The deep flanges on reels D6 are placed so close that the rope goes on winding
upon itself increasing the diameter and consequent speed at every part of their
revolutions, the power required decreasing in an equal ratio as the ladders come
towards the vertical position. When the reels are rotated the outer end of the
swinging or raising frame R 1, gradually rises, acting with a thrust on the ful-
crum pin in brackets R at its base, forcing the ladders upwards by the two friction
rollers R3 and sustaining them at any desired point. The ladder and raising
frame being pivated on different centres the rollers R3 will traverse the roller
path R4, for some distance in the process of rising.
In my improved form of crank handle the stock H is of forged steel or other
metal, bored out from end to end on different centres for the piston catches H1
and H2, bored across the centre boss to go over the swelled end of first motion
shaft I), recessed on inner face to receive the slotted flange C6 on the pinion for
slueing motion, and recessed on front to receive the slotted flange I) 1 for raising
motion, the sliding catches extend through a screwed stop H4 in each head, and
are provided with small levers H 3, secured by nuts H6, but swivelling freely on
the extensions, the stops H4 have a spiral path raised upon them and a stop
notch for each which retains the catches out of gear. And the catches are made
to engage with the slots in flanges D1 or C6 by spiral springs H5 within the
stock.
By throwing in the catch H1 the ladders may be raised or lowered, and by
the catch H2 in gear they may be slued around into any desired position, both
operations are independent of each other, but may be performed simultaneously.
I also provide ladders in connection with a turn-table with an alternative
method of raising and slueing, and use for this purpose a tubular braced, wrot
metal, or wood lever K fixed rigidly to the keel at D7 with stays K 1 fixed to

page_text: the sides of main ladder, the outer portion of the lever K2 is hinged and folds
over the rigid part when travelling and is provided with a pair of spring catches
at K3, which automatically fixes the lever when turned over into position for
use. K4 are wire rope stays from lever to head of main ladder to increase the
rigidity.
In connection and combined with the improved fire escape herein described I
provide one single trussed ladder N and one pair of light trussed extensible
ladders O. So placed as to be clear of the main ladders when travelling or
working, and capable of being easily withdrawn and used independently for any
purpose or of being spliced on to the top of main sliding ladder by means of
spring clips and adding the additional length thereto.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I claim
is:
-
First The application of a geared turn-table in which extensible ladders
are pivatted to fire escapes, combined with an arrangement for slueing or turning
the ladders in any direction within a complete circle, by means of a crank handle
actuated from a fixed point in the base, and from the ground level, substantially
as and for the purpose above specified.
Second-The combination with a turn-table of improved means whereby I
raise the extensible ladders from the horizontal position to the vertical without
any previous adjustment of parts or disconnecting them from the truck which I
make the base for all operations and utilize its weight to counterbalance the
ladders when extended.
Third The improved form of crank handle capable of two direct independent
or simultaneous motions, and reversing, also applicable to other purposes.
Fourth Improved arrangement for equalizing the strain on double lifting ropes.
Fifth Improved form of metallic cap for sides of extension ladders.
Sixth Improved means for carrying auxillery ladders in a fire escape without
interference with the main extensible ladders.
Seventh The improved portable fire escape and extensible ladders constructed
substantially as described with reference to the accompanying two sheets of draw-
ings.
T
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