Improvements in Lowering Cranes, specially applicable for Use as Fire Escapes.
Year: 1894

page_text: Date of Application, 9th May, 1894
Complete Specification Left 11th Feb.. 1895-4ccepted, 30th Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in Lowering Cranes, specially applicable for Use
as Fire Escapes.
We, WILLIAM JAMES ALLEN, of 19 Herbert Street, Brithdir, Glamorganshire,
Mason, DAVID WILLIAMS, Thomas Street, New Tredegar. Monmouthshire,
Mason, and VICTOR LECOQ, Thomas Street, New Tredegar, Monmouth-
shire, Mason, do hereby declare the nature of this invention to be as follows:-
Our invention relates to lowering cranes, which are specially though not
exclusively applicable for use as fire escapes.
The object of our invention is to obtain a lowering crane which will permit of
manner that no
the object to be lowered to be passed to the ground in such a
injury may be sustained by it either from striking against objects in descent, too
rapid passage through the air or from striking the ground violently.
In carrying our invention into effect we employ a device similar to an ordinary
wall crane and cap.ble of moving angularly round its post so as either to lie flat
against the wall, generally under the architrave of a window, or to project at right
angles thereto. The said crane has a telescopic and adjustable arm or jib the inner
tube of which slides freely by means of friction wheels within the larger tube and
The said jib
may be fixed in any desired position by means of a binding screw.
carries at its free end a device which we shall hereinafter term the speed-varying
device. The said speed-varying device is constructed as follows. Over a pulley
resembling a sprocket wheel passes the chain or rope by means of which the bodies
are lowered to the ground when required. The said pulley transmits movement
to an air admission valve of such construction that air is passed through it at a
varying rate, slowly at first, then more rapidly and then more slowly again: that
is to say air is slowly passed when the body on the lowering rope begins to
descend, passes with increasing rapidity as the body approaches the middle of its
course towards the ground, and then passes with decreasing velocity until the body
reaches the ground. A convenient form of air admission valve consists of a
cylinder, bereinafter termed the valve cylinder, within which works a hollow piston.
The hollow piston is threaded upon a spindle placed in the geometric axis of the
valve cylinder. This spindle is caused to rotate by any convenient transmitting
device actuated by the lowering pulley; and in rotating it causes the hollow piston
suitably guided to travel longitudinally within the valve cylinder. In a side wall
of the hollow piston is a series of orifices, and in the wall of the valve cylinder is
a wide port whose width equals the distance between the extreme orifices of the
serius mentioned. As these orifices come opposite the wide port more air passes.
When they are all opposite the sad port the largest possible amount of air passes.
As onward travel of the piston takes place fewer and fewer orifices are opposite
the ort and less and less air passes, till at last when one of the orifices are
opposite the port no air passes at all. The air thus passed is admitted under the
Within the said cylinder,
variations mentioned to the cylinder of an air pump.
hereinafter termed the air punip cylinder, a tight piston is caused to reciprocate
by means of suitable transmitting devices connecting the said piston with the
When no air is admitted through
lowering pulley herein before mentioned.
the air admission valve to the air pump cylinder the tight piston reciprocates with
difficulty and as will be understood the ease and there.re the speed of reciprocation
will vary with the amount of air admitted. An effective dash-pot is thus obtained.

page_text: The lowering chain or rope passing over the lowering pulley may be passed over
suitable guide pulleys into the room or compartment opposite which the crane is
placed and there coiled on a drum or arranged in a suitable receptacle. When
instead of a tail rope an endless rope is employed a loop of the said rope is passed
into the room or compartment as in the manner before mentioned.
A rack and
pinion device or its equivalent may be employed to raise or lower the whole crane
when desired.
The action of our invention is as follows. Let us assume that the crane is used
as a fire escape and that a tail rope is employed. When an alarm of fire is received
the person desiring to escape pushes the crane out into its extended position and
passes the body strap which may be at the free end of the rope over his body and
jumps clear. He is then free to descend. His weight causes the lowering pulley
to rotate. This actuates the air admission valve which at first passes but little
air to the air pump cylinder so that the tight piston works slowly. As more air
is admitted the piston reciprocates more rapidly till when the escaping person is
half-way to the ground he is descending at the greatest velocity. Less air is now
admitted, the piston reciprocates more and more slowly till at last the escaping
person reaches the ground softly. By this time the other end of the rope has
passed out of the compartment in which it was and is now hanging close up to the
lowering pulley ready for a second escaping person to use the apparatus. If this
be done the sero d person descends exactly as did the first one, the apparatus
going through the same cycle of operations as before but in the reverse direction.
An indefinite number of persons can escape in this way one after the other.
If instead of a tail rope an endless rope is employed the action is the same as
before after the loop has been run out from the compartment where it was.
The
endless rope presents certain advantages when the crane is at a great height,
inasmuch as the rope being balanced on the lowering pulley its weight does not
affect the working of the apparatus.
We contemplate, as a transmitting device connecting the piston in the air pump
with the lowering pulley, the employment of a combination of links, eccentric and
toothed wheels, the latter arranged for the purposes of alteration of speed after the
manner of the back gear of a lathe.
COMPLETE SPECIFICATION.
Improvements in Lowering Cranes, specially applicable for Use
as Fire Escapes.
We, WILLIAM JAMES ALLEN, of 19 Herbert Street, Brithdir, Glamorgan-
shire, Mason, DAVID WILLIAMS, Thomas Street, New Tredegar, Monmouthshire,
Mason, and VICTOR LECOQ, Thomas Street, New Tredegar, Monmouthshire,
Mason, 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 :-
Our invention relates to lowering cranes, which are specially though not
exclusively applicable for use as fire escapes.
The object of our invention is to obtain a lowering crane which will permit of
the object to be lowered to be passed to the ground in such a manner that no
injury may be sustained by it either from striking against objects in descent, too
rapid passage through the air or from striking the ground violently.

page_text: any g
Figure I is a front elevation of the crane in its normal position.
Figure II is an end view part section and part elevation of the head of the
crane jib, viewed from the post, and with a few parts removed for clearness.
Figure 1 shows a side elevation of the gearing in the crane head.
Figure IV shows a plan of one of the levers.
Figure V shows a plan of the slide-valve top.
Figure VI is a plan view of an adjustable bearing which is fixed in the side of
the head of the jib.
In carrying our invention into effect we employ a crane somewhat similar to an
ordinary wall crane which is capable of angular movement round its post so as
either to lie flat against the wall, generally under the architrave of a window, or
to project at right angles thereto. The said crane has a telescopic and adjustable
arm or jib the inner tube or arm B of which slides freely, by means of the two
friction wheels or rollers b h which are fitted on the inner tube or arm B, within
the larger tube A. 1 is a binding screw which may be used to lock the tube B
in any desired position. The said tube or arm B carries at its free end a head or
device which will hereinafter be termed the speed-varying device C. This device C
is shown in Figure I with one side of its case removed and in Figure II on a
larger scale. The said device C is constructed as follows. Over a sprocket wheel
pulley D passes the chain E by means of which the bodies are lowered to the
ground when required. The said pulley D is cogged on one side or flange d and
is keyed to the spindle F which is capable of rotation in the bearings (Figure II)
fixed on the sides of the frame c¹. G is a cogwheel fixed on the spindle H which
is carried by the bearings hh fixed to the frame c¹. The wheel G gears with the
flange & of pulley D. Fixed also on the spindle H is a spurwheel J which gears
with the pinion K which is fixed on the spindle L which turns in the bearings 1, 1
fixed to the frame. On the spindle L is also a pinion M which gears direct with
the flanged of pulley D when the said spindle L is moved to the right in the
direction of its length so that the wheel K no longer engages with the wheel J.
At both ends of the spindle are the catches 112, bearing against the end of the
spindle L when the high speed gear d, G, J and K are in use, and bearing
against the other end of the spindle when the slow speed gearing d M is in action.
On the spindle L is also an eccentric wheel N fixed to a guide wheel N¹. A
feather way is cut through N N and the feather fixed in spindle L permits
N N¹ to slide on it. The guide wheel N engages with a bracket c³ (shown in
dotted lines in Figure III) which is fixed to the curved part of the frame c'.
whereby the eccentric wheel N is maintained in one position whether the spindle L
is moved either in or out that is to say to the right or left. On the eccentric N
(see Figure III) is fitted the eccentric-strap n' to the upper side of which is
journalled the spindle n of the L-shaped lever n³. The lever n³ is pivoted by its
spindle to the bracket shown by dotted lines, so that the free end of the said
lever n³ is given an angular reciprocating motion by the rotation of the eccentric N.
The lever n (see Figure IV) terminates at its free end in a fork-shaped piece with
inwardly pointing spindles non. On these are journalled two levers n n which at
their other ends are connected by means of spindles n' (see Figure 1) to the sides of
a boss n on the piston-rod o of the piston O shown in section. The levers nº º
convert the angular reciprocating motion of the lever n' into a rectilinear horizontai
reciprocating motion of the piston-rod o. The said piston-rod o (see Figure I) slides
in the bearing o¹ fixed in the end of the arin B (in some cases we allow the piston
to slide in a bearing fixed in the open end of the cylinder) and the other end of
the said piston-rod is connected to a piston O which slides in an airtight manner
in the cylinder P of the air pump shown partly in section in Figure 1. By means
of this arrangement of parts a horizontal movement is given to the piston of the
air pump (which thus acts as a dash-pot) by means of the rotation of the pulley D
and the intermediate gearing herein before described; and_motion is given to the
pulley D by a descending body causing the rope or chain E to travel.

page_text: In Figure II is seen an end view of the cylinder P with the piston removed.
p is a passage shown by dotted lines near the closed end of the cylinder P. This
passage communicates with a pipe p' shown in section which is capable of being
opened when desired by means of a union. The said pipe communicates with
a port of cut in the cylinder g¹ of a cylindrical slide valve Q. The said cylindrical
slide valve is shown partly in section in Figure 11. The cylinder q¹ is open to
the air at its upper end see Figure V. A screwed spindle q2 runs through the
axis of the cylinder and is retained in bearings in its top and bottom. On the
spindle 2 is a hollow cylindrical slide y³ threaded at its top and bottom ends so
as to engage with the thread of the spindle q. This slide 3 fits in an air-tight
manner in the cylinder gl but is open at its upper and lower ends to the air, and
a series of port holes is cut in that part of the said slide that is in contact with
the port q when the said slide is half way on its travel. The port holes y are cut
at such positions that the top and bottom ones coincide with the top and bottom
of the port g, when the said port holes are opposite the said port. The slide y³
being a little more than three times the length of the port a space slightly greater
than the length of the port q is left above and beneath the port holes g*.
Figure II shows the slide 3 almost at the top of its path, and the port q closed
by the lower part of the slide q³. To the lower end of the spindle q2 is keyel a
bevel wheel R which engages with a bevel wheel on the main spindle F and is
driven by it.
The wheel R is pressed against the wheel R₁ by means of an
adjustable bearing S (indicated in dotted lines in Figure III and shown separately
in Figure VI) which engages with the spindle q. To prevent the slide g³
turning, a pin g protrudes from the side of the slide q³, and slides in a slot 7
cut in the case ' (Figures 1 and III) and also in the cover of C, the case q' being
partly let into the cover c¹ of C as is seen in Figure 11. In Figure 1 the post T
is seen placed at the side of a window for symmetry, and into a recess t cut in its
side the end of the head C may be slid. The other post T is securely held by
the bearing blocks t and t' and is in rigid connection with the jib. U is a case
shown in section, which contains a guide wheel u' and a jockey wheel u². The
wheel u guides the chain or rope E to or from the post T' through orifices cut
in the case U and the post T. The wheel u² keeps the chain or rope E on the
wheel u¹. and u are two guide wheels which may be used to support the
chain or rope E in festoons when in rest or they may be used for it to run on,
though it generally runs free of them when in use. is a jockey wheel to keep
the chain on the pulley wheel D. V is a rack and pinion operated by a handle v
so that the apparatus may be raised so as not to cut off too much light from the
window where it is placed when the crane is not in use. is a guide for the rack.
The rack and pinion device is also used to lower the crane in case of need for use.
The crane is held in its raised position by the handle of the winch being doubled
over into the hole in the post T₁. The chain or rope E may be conducted over
suitable guide pulleys into the room and coiled on a drum if required. In the case
of the chain or rope being an endless one a bight or loop is taken into the room.
In the case of a tail rope or chaiu as in Figure I a body strap may be fixed at
each end. When body straps are employed in the case of an endless rope or chain
they are placed half the length of the rope or chain apart.
In order that the action of our invention may be readily understood we shall
proceed to describe its use as a fire escape and we shall assume that a tail rope
is employed.
In this case the body of the person wishing to escape is fastened to the body
strap at one end of the rope if it be at the top, and the jib is then placed at right
angles to the wall. On jumping clear the weight of the body causes the rope or
chain E to descend, and the pulley D to rotate. The slide is in the position
shown in Figure II, in starting, and the port 9 closed by the lower part of the
slide being over it, so that the pulley D can only move the piston O slowly
because it is working in a closed dashpot. As the body descends the air is given
freer ingress and egress because the rotation of the spindle q by the bevel

page_text: wheels R and R has brought down the said slide 3 so that more and more of the
port holes g' are opposite the port q. When the body is halfway to the ground
the port-holes g are all opposite the port y, consequently the speed of descent
is at its greatest, air being freely admitted and expelled by the piston O. As the
body nears the ground the speed is lessened by a smaller number of port holes q¹
being over the port q. When the body is about to touch the ground the speed
of descent is at its minimum because all port-holes q₁ are now pist the port and
no air is admitted or expelled. The body strap at the other end of the tail rope
is now in a position for the next descent, the pulley and apparatus working in the
reverse direction but going through the same cycle of operations and giving the
same results as before. The speed at which bodies are lowered to the ground will
vary according as the shaft L is in the position shown in Figure 1 or is moved
to the right so as to bring the wheel M into engagement with cogged flange d as
hereinbefore explained.
We have hereinbefore spoken of the series of port holes gf being cut at such
positions that the top and bottom ones comeide with the top and bottom of the
porty when the said port holes are opposite the said port, or in other words that
In such case it will
the series of port holes q is of equal length to the port q.
follow that when a body is being lowered its velocity gradually increases to a
maximum, is at that maximum only momentarily, and then gradually diminishes.
When however we are dealing with great heights, it is frequently desirable to
When this
retain the velocity at its maximum for a considerable period of time.
is the case we find it convenient to increase the length of the spindle q², slide q³
and series of port holes y but without increasing the length of port q. By this
means, as will be readily understood the port q is unobstructed for a longer period,
and the maximum velocity sustained.
In describing the action of our invention we have referred to the employment of
a rope whereas in the drawings we have shown pulley D as a sprocket wheel. It
will of course be understood with such a sprocket wheel we employ a suitable
chain and that when we employ a rope we use a suitable form of rope gripping
pulley instead of the sprocket wheel.
We desire it to be understood that we do not limit ourselves to the specific form
of apparatus shown as it is obvious that any competent engineer having grasped
the principle of our invention may modily its details to an indefinite extent without
departing from its spirit.
We sometimes find it convenient to attach a small release tap to the closed end
of the air pump cylinder so that on being opened it allows free passage of air when
it is desired to rapidly haul the chain or rope.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :
1. The new or improved lowering crane substantially as set forth.
2. In a lowering crane the speed varying device substantially as set forth.
3. In the speed varying device of a lowering crane the employment, in combina-
tion, of an air pump or dash-pot and a slide valve the said slide valve varying the
admission of air to the said pump or dash-pot substantially as set forth.
4. The arrangement and combination of parts substantially as set forth with
reference to Figures 1 to 6 inclusive.
This oah da
Wohruary 1805
Dated this 9th day
February 1905
For the Applicants,
J. G. LORRAIN, M Inst. E.E., M. Inst. M.E.,
Norfolk House, Nortolk Street, Strand, London, W.C.,
Chartered Patent Agent.