improvements in the construction of fire escapes and ladders
Year: 1896

page_text: Date of Application, 14th Apr., 1896
Complete Specification Left, 13th Jan., 1897-Accepted, 14th Apr., 1897
I, JAMES COMPTON MERRYWEATHER of Greenwich Road, Greenwich, in the
County of Kent, Engineer do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in the construction of fire escapes and
ladders.
One part of this invention consists in the construction of ladders in which the
treads or rungs are of an oval or oblong section, the rungs secured to the ladder
sides by fitting them in dovetail sockets which are attached inside the ladder side
by means of screws. The rungs or treads are driven downwards from the top and
rest on the bottom of the sockets. One or more rungs may be removed froin the
ladder by driving upwards out of the socket, without disturbing the rest of the
rungs, or taking the ladder sides apart.
Another improvement in the construction of ladders consists in stiffening and
strengthening the ladders sides by means of tee, or other suitable section metal, or
of tubes applied in the form of a bowstring girder to the upper edge of the ladder
sides and stayed at intervals to the ladder sides by tension pieces, preferably of
tube, in order to give lateral stiffness to the bowstring girder.
Another part of this invention relates to the method of raising escape ladders,
which are run in a horizontal position, to an upright position for use. One method"
of carrying out this part of my invention is as follows,-A drum is fixed upon a
shaft revolving in bearings attached at or near the bottom of the main ladder;
a wire rope is wound upon this drum, the free end being secured to the bottom of
the box, or to the axle, or to some suitable part of the carriage. The drum is
provided with two ratchet wheels, one for retaining it in position as it is rotated,
and the other to be actuated by a pawl on a hand lever to which the power is
applied. The drum is also fitted with a brake operated upou by the ratchet lever.
In raising the ladder the lever is reciprocated to revolve the drum and the rope
attached to the frame or other fixed part draws the foot of the ladder inwards
until the ladder assumes an approximately vertical position. The ladder is secured
in this position by means of a catch on the frame or box and by the fixed pawl on
the drum ratchet. In lowering, the catches and pawls are released and the brake
applied to the drum by the hand lever to which the raising pawl is attached, thus
regulating the speed of the descent.
Another part of my invention relates to arrangements for plumbing or rendering
the ladder vertical laterally when standing on hilly or uneven ground. One
method of carrying out this part of my invention consists in pivotting the arms
carrying the ladder ou a fixed centre in front of the carriage and giving lateral
motion to the bracket by means of a screw rotating between collars on the bracket
and traversing in a nut fixed on the front of the carriage. The lateral movement
of the foot of the ladder is provided for in one method by pivotting an axle at the
centre of the bottom of the main ladder, and providing two wheels with curved
tyres to slide along the ground while the axle is free to rock on the pivot, and in
another way by curving the stretcher at the bottom of the main ladder to a radius
struck from the centre upon which the ladder oscillates.

page_text: Another method for providing for the plumbing of the escape is to fit two
adjusting screws with hand wheels, one near each end of the main axle of the
carriage, by means of which the carriage together with the ladders is tilted as
required.
Dated this 12th dow of Anril 1906
Improvements in Fire Escapes and Ladders.
I, JAMES COMPTON MERRYWEATHER of Greenwich Road, Greenwich, in the
County of Kent, 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 :-
My invention relates to improvements in the construction of fire escapes and
ladders.
One part of this invention consists in the construction of ladders in which the
treads or rungs are of an oval or oblong section, the rungs secured to the ladder
sides by fitting them in dovetail sockets which are attached inside the ladder side
by means of screws. The rungs or treads are driven downwards from the top and
rest on the bottom of the sockets. One or more rungs may be removed from the
ladder by driving upwards out of the socket without disturbing the rest of the
rungs, or taking the ladder sides apart.
Another improvement in the construction of ladders consists in stiffening and
strengthening the ladders sides by means of tee, or other suitable section metal, of
tubes, or wood, applied in the form of a bowstring girder to the upper edge of the
ladder sides and stayed at intervals to the ladder sides by tension pieces, preferably
of tube, in order to give lateral stiffness to the bowstring girder.
Another part of this invention relates to the method of raising escape ladders,
which are run in a horizontal position, to an upright position for use. One method
of carrying out this part of the invention is as follows;-A drum is fixed upon a
shaft revolving in bearings attached at, or near, the bottom' of the main ladder;
a wire rope is wound upon this drum, the free end being secured to the bottom of
the box or to the axle, or to some suitable part of the carriage. The drum is
provided with two ratchet wheels, one for retaining it in position as it is rotated,
and the other to be actuated by a pawl, or a hand lever to which the power is
applied. The drum is also fitted with a brake operated upon by the ratchet lever.
In raising the ladder the carriage is tipped until the foot of the ladder rests on the
ground the lever is reciprocated to revolve the drum and the rope attached to the
frame or other fixed part draws the foot of the ladder inwards until the ladder
arrives at the end of its travel on the carriage and the ladder assumes an
approximately vertical position. The ladder is secured in this position by means
of a catch on the frame or box and by the fixed pawl on the drum ratchet. In
lowering, the catches and pawls are released and the brake applied to the drum
by the hand lever to which the raising pawl is attached, thus regulating the speed
of the descent. In some cases I make one ratchet wheel to serve the two purposes
of retaining the drum while a fresh purchase is being taken with the ratchet lever,
and of being rotated by the pawl on the ratchet lever. On one side of the ratchet
wheel, and preferably in the same piece with it, I construct a smooth circumferential
portion which is acted on by the brake. I construct the retaining pawl and brake
in one piece, and arrange it so that the brake can be applied by the ratchet lever
and the retaining pawl thrown out of gear at the same time.

page_text: Another part of my invention relates to arrangements for plumbing or rendering
the ladder vertical laterally when standing on hilly or uneven ground. One
method of carrying out this part of my invention consists in pivotting the frame
carrying the ladder on a fixed centre in front of the carriage and giving lateral
motion to it by means of a screw rotating between collars on the frame and
traversing in a nut fixed on the front of the carriage. The lateral movement of
the foot of the ladder is provided for in one method by pivotting an axle at the
centre of the bottom of the main ladder, and providing two wheels with curved
tyres to slide along the ground while the axle is free to rock on the pivot, and in
another way by curving the stretcher at the bottom of the main ladder to a radius
struck from the centre upon which the ladder oscillates.
Another method for providing for the plumbing of the escape is to fit two
adjusting screws with hand wheels, one near each end of the main axle of the
carriage, by means of which the carriage together with the ladders is tilted as
required.
In the accompanying drawings;-
Figure 1, Sheet 1, shews an elevation of the general arrangement of the escape
when in its horizontal or travelling position.
Figure 2, Sheet 1, shews a plan of the same.
Figures 3 & 4, Sheet 2, shew the improved form of rung or tread and the method
of fixing it to the ladder side by means of the dovetail socket.
Figure 5, Sheet 2, shews the method of stiffening the ladder sides by means of a
trussing member in the form of a bowstring girder.
Figures 6, 7 & 8, Sheet 2, shew various methods of securing the trussing
member when composed of different materials.
Figures 9 & 10, Sheet 2, shew the apparatus for raising the ladders in their
vertical position.
Figures 11 & 12, Sheet 2, shew methods of constructing the feet of the ladders
when used on hilly or uneven ground.
Figures 12 & 13, Sheet 2, shew a method of adjusting the ladders vertically
when used on hilly or uneven ground.
A,
In Figures 1 & 2, Sheet 1, Ä, is the bowstring girder. B, is the apparatus used
for raising the ladders, which is shewn in detail in Figures 9 & 10, Sheet 2.
C, is the frame for carrying the ladders which is pivotted at the fixed centre D to
the carriage E. The frame C is attached to the back end of the carriage E by
means of suitable clips engaging with the guides H. H. Lateral motion is given
either way to the frame by means of the screw F revolving in suitable bearing
on the frame and engaging with the nut G which is fixed to the carriage E.
K, is the axle at foot of the ladders pivotted at L, and provided with wheels with
curved tyres M. M.
In Figures 3 & 4, Sheet 2, 1, is the ladder rung, or tread. 2, is the ladder side.
3, is the socket with dovetails 4.
In Figure 5, Sheet 2; 5 is the ladder side, 6 is the bowstring trussing member,
7. 7. are the tension pieces, 8. 8. are the sockets for securing the ends of the truss
to the ladder sides, and when a wooden truss is used, as shewn in Figure 7, the
sockets are formed similar to Figures 3 & 4.
In Figures 6, 7 & 8, Sheet 2; the trussing members 9, 10 & 11 are shown
constructed respectively of T section metal, of wood, and of metal tube.
In Figures 9 & 10, Sheet 2; the mechanism for raising the ladders is shewn in
detail, the case being taken when the ratchet wheel is combined with the brake
drum and when it serves the purpose of retaining the winding drum and of being
actuated by the lever and pawl. 12, is the drum around which winds the wire rope,
one end of which is fixed to the carriage. 13, is the combined ratchet wheel and
brake drum. 14, is the lever, and 15, is the pawl. 16, is the shaft, and 17, are
the bearings in which it revolves. The ratchet wheel 13 is rotated by the recipro-
cation of the lever 14 and pawl 15, thus revolving the drum 12. The drum 13 is
retained in position while a fresh purchase is taken, by the pawl 18. 19, is the

page_text: brake constructed in the same piece as the pawl 18, and is applied to the plain
circumferential portion 20 of the ratchet wheel 13 by the lever 14 being depressed,
and the portion 21 of the lever being brought into contact with the portion 22 of
the brake, the pawl 15 is of course first thrown out of gear, and it will be seen that
upon the application of the brake the pawl 18 will become disengaged and allow
the drum 12 to revolve freely. In the same figures, 23, is the ladder, 24, is the
back lever, 25. 25. are the wheels at foot of ladder to facilitate raising the same.
In Figure 11, Sheet 2; 26, is the axle at foot of ladder 27, carrying wheels 28
with curved tyres, and 29 is the pin upon which the axle is pivotted.
In Figure 12, Sheet 2; the curved stretcher is shewn at 30.
. In Figures 12 and 13, Sheet 2; 31, are the adjusting screws working in ball
and socket joints 32. 33, is the axle. 34, is the ladder carriage and 35, are the
springs.
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 ;-
1. The method of fixing rungs or steps to a ladder side substantially as
illustrated and described.
2. The application of a trussing member to the sides of a ladder in the form of
a bowstring girder as illustrated and described.
3. The apparatus used for bringing the ladders from their horizontal to vertical
position, by means of a ratchet and pawl motion combined with a brake substantially
as illustrated and described.
4. The apparatus used for adjusting the ladders vertically when on hilly, or
uneven, ground, consisting of screws working in the axle and attached to the
carriage, as shewn in connection with Figures 12 & 13, Sheet 2, by means of ball
and socket joints substantially as illustrated and described.
5. The apparatus used for adjusting the foot of the ladders on hilly, or uneven,
ground, consisting of a pair of wheels working on a pivotted axle.
6. The application of a curved stretcher to the foot of the ladder for permitting
its lateral adjustment when working on hilly, or uneven, ground.
Dated this 13th day of January 1897.
J. C. MERRYWEATHER.