Improved Apparatus for use as a Fire Escape and for Raising and Lowering Persons or Materials generally.
Year: 1899

page_text: Date of Application, 25th Apr., 1899
Complete Specification Left, 1st May, 1899-Accepted, 17th June, 1899
Improved Apparatus for use as a Fire Escape and for Raising and
Lowering Persons or Materials generally.
We, JAMES OMAR MILLER (Inventor), and DANIEL AGNEW (Inventor), both of
Rochester, in the County of Fulton and State of Indiana, United States of
America, do hereby declare the nature of this invention to be as follows:-
1
This invention relates to apparatus more especially designed to serve as a
portable fire escape but applicable also for raising and lowering persons or
materials generally, as for example in mines and shafts and for workmen who
have occasion, in the case of buildings, to ascend to and descend from considerable
heights.
The apparatus consists essentially of a cord-carrying drum mounted within a
casing having toothed wheels connected to the drum and reciprocating bara
having projecting points engaging the teeth of said wheels, thus providing an
escapement mechanism which will prevent a too-rapid rotation of the drum
under the weight of the user or load. It further consists in bars pivoted at one
end and carrying friction devices adapted to engage the cord and at the other
end having links connected opposite bars, to which links is connected the weight
supporting mechanism in such a manner as to clamp the friction devices upon
the cord, and also of a cam mechanism by which the pressure of said friction
devices may be released at will.
The
The drum consists of a central barrel having flanges between which the cord is
wound the toothed wheels being fixed upon the outside of said flanges. These
wheels should have an odd number of teeth so that the point of one tooth is
diametrically opposite the space between two other teeth. Moreover the two
wheels should be arranged so that their teeth alternate with each other.
shaft of the drum extends outwards and is provided with journals fitting within
apertures in the casing. The outer ends of the shaft are provided with squared
ends or are arranged in any other manner so that the crank may be placed upon
either end. The casing is hollowed out so as to receive the drum with the toothed
wheels and also the reciprocating bars. At the centre the bars are provided with
slots adapted to embrace the shaft of the drum and at each end they are provided
with a side projecting point, or tooth, adapted to engage the teeth upon the
wheels. At one end said bars are also provided with openings adapted to receive
a lever which has a central pivot pin fitting within recesses in the casing. The
outer ends of the lever may project through the casing and be provided with
apertures adapted to receive a cord when desired. By means of this connection
and also the arrangement of the teeth upon the two wheels the motion of the
bars is alternate-that is while one is moving in one direction the other is moving
in the opposite direction.
The casing is provided with recesses adapted to receive the ends of the bars
and compel them to move in a straight line, the edges of the bars closely fitting
the recesses. The casing is also preferably provided with recesses which embrace

page_text: and entirely cover the toothed wheels. The recesses may if desired be continued
EO as to also cover the drum. Mounted in the upper end of the casing are the
guide rollers between which the cord passes as it leaves the casing. Near the
upper end of casing are pivot. bolts to which levers are pivoted, said levers
extending longitudinally of the casing and carrying near their pivot ends pivot
bolts on which friction rollers are mounted to rotate, the casing is provided with
apertures which receive the bolts and permit them to have a slight lateral
motion. To the lower ends of the levers are pivoted links which have their outer
ends connected to each other thus forming a toggle joint. The bolt forming the
central pivot for the toggle joint passes through a slot in the casing and also
forms a pivot for a stirrup to which a belt or other suitable means is attached
by which the user may suspend his weight from the fire escape.
This
It is obvious that when a weight is suspended from the stirrup the links form-
ing the toggle joint connection between the levers will be pulled down at their
inner ends thus drawing the levers towards each other and firmly clamping the
suspending cord between the friction rollers. This will result in checking or
entirely stopping the descent of the body held in the belt depending upon the
adjustment of the parts. If it is desired to release the friction on the cord so that
the descent will be more rapid, this may be accomplished by means of a cam
which has a pivot or axis journalled in the lower end of the casing, the pivot
being arranged near one end of the cam which is simply an eccentric.
eccentric or cam is provided with recesses adapted to receive a pin by means of
which the cam or eccentric may be rotated. The bolt from which the stirrup is
suspended is located directly above the cani or eccentric. By rotating the cam
the bolt will be raised, thus raising the links and forcing the levers farther apart.
This operation releases the hold of the friction rollers upon the suspending cord.
The outer surface of the cam or eccentric is provided with transverse notches
adapted, when the cam is sufficiently rotated, to engage the bolt and in such
case the cam will be held by the engagement of the pin with the transverse notch
and the backward rotation of the cam be prevented.
The
The descent of the body held in the belt will be regulated to great degree by
the operation of the escapement devices herein before described, consisting of
the toothed wheels and the reciprocating bars which will act like any escape-
ment to limit the speed of rotation of the drum. This speed of rotation is further
regulated through the action of the friction devices described, and the cam.
parts may be so proportioned that when the weight is suspended entirely from
the toggle joint connections, consisting of the links the friction devices will clamp
the suspending cord with sufficient force to check the descent of the body and
in this case the cam may be operated so as to make the descent as slow or as rapid
as desired. Preferably, however, the parts should be so proportioned that there
will be a slow descent even when the cam is not in use.
The device is also preferably provided with crank arms having handles at their
outer ends adapted to be engaged by the hands of the user, and by means of these
arms the speed of descent may also be regulated if desired. By using the crank
arms the device may also be used as a hoisting apparatus. The ratchet mechanism
which regulates the speed of descent is such that it will create but small friction
when slowly operated.
The friction clamping devices consisting of the rollers and the levers by which
they are controlled, may be thrown entirely out of operation by properly placing
the cam and in this event by rotating the crank arm the user may hoist himself.
The crank arms may be arranged so as to be easily removed if desired.
T11: ORAL
A
1000
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.

page_text: Figure 3 is a side view of the device with one-half of the casing removed;
Figure 4 is a side view of the drum and the toothed wheels connected thereto;
Figure 5 is a detail showing the reciprocating bars which engage the teeth
upon the wheels;
Figure 6 is a longitudinal section taken through one-half of the casing; and
Figure 7 is a detail showing the construction of the cam by which the cord
clamping mechanism is released.
Our device is intended to be used more particularly for a fire-escape, but, as
will be hereinafter pointed out, is capable of use for other purposes. It comprises
a drum which consists of a central barrel C² and flanges C, between which the
cord C is wound. Upon the outside of these flanges are fixed the toothed wheels (.
These wheels should have an odd number of teeth, so that the point of one toot!
is diametrically opposite the space between two other teeth. Moreover, the two
wheels should be arranged so that their teeth alternate with each other, (as shown
by the solid and dotted lines in Figure 3). The shaft of the drum extends out-
ward and is provided with journals C4, fitting within apertures in the casing A.
The outer ends of the shaft are provided with squared ends C5 or are arranged in
any other manner, so that a crank may be placed upon either end. The casing A
is hollowed out so as to receive the drum with the toothed wheels C and also
the reciprocating bars B (which latter are shown in edge view in Figure 5, and
in-side view in Figure 3). At the centre the bars are provided with slots B³,
adapted to embrace the shaft of the drum, and at each end they are provided with
a side projecting point or tooth b adapted to engage the teeth upon the wheels C.
At one end said bars are also provided with openings B¹, adapted to receive the
lever 1, which has a central pivot-pin 11 fitting within recesses in the casing.
The outer ends of the lever may project through the casing, as shown in Figure 1.

page_text: and be provided with apertures adapted to receive a cord when desired. By
means of this connection and also the arrangement of the teeth upon the two
wheels C the motion of the bars B is alternate-that is, while one is moving in
one direction the other is moving in the opposite direction.
The casing A is provided with recesses A¹, adapted to receive the ends of the
bars B and compel them to move in a straight line, the edges of the bars B
closely fitting the recesses A¹ The casing is also preferably provided with
recesses A2, which embrace and entirely cover the toothed wheels C. The recesses
may, if desired, be continued so as to also cover the drum.
Mounted in the upper end of the casing are the guide rollers J, between which
the cord C passes as it leaves the casing. Near the upper end of the casing are
pivot bolts E, to which are pivoted the levers E, extending longitudinally of the
casing and carrying near their pivot ends pivot bolts E2 upon which are mounted
to rotate friction rollers F.
The casing A is provided with apertures, which receive the bolts E² and permit
To the lower ends of the levers E are
them to have a slight lateral motion.
pivoted at e links e, which have their outer ends connected to each other, thus
forming a toggle-joint. The bolt el forming the central pivot for the toggle-joint,
passes through a slot A in the casing and also forms a pivot for the stirrup H,
to which a belt I or other suitable means is attached by which the user may
suspend his weight from the fire escape.
It is obvious that when a weight is suspended from the stirrup H the links e,
forming the toggle-joint connection between the levers E, will be pulled down
at their inner ends, thus drawing the levers E toward each other and firmly
clamping the suspending cord C³ between the friction rollers F. This will result
in checking or entirely stopping the descent of the body held in the belt I,
depending upon the adjustment of the parts. If it is desired to release the friction
on the cord C, so that the descent will be more rapid, this may be accomplished
by means of the cam G, which has a pivot or axis G journalled in the lower end
of the casing, the pivot being arranged near one edge of the cam, which, as shown
in the drawings, is simply an eccentric. This eccentric or cam is provided with
recesses g, adapted to receive a pin G¹, by means of which the cam or eccentric
may be rotated.
As shown in Figure 7, the bolt from which the stirrup H is suspended, is
located directly above the cam or eccentric. By rotating the cam in the manner
shown by dotted lines in Figure 7, the bolt c¹ will be raised, thus raising the
links e and forcing the levers E farther apart. This operation releases the hold
of the friction rollers F upon the suspending cord C. The outer surface of the
cam or eccentric G is provided with transverse notches g, adapted when the cam
is sufficiently rotated to engage the bolt e¹, and in such case the cam will be held
by the engagement of the pin e¹ with the transverse notchy and the backward
rotation of the cam be prevented.
The descent of the body held in the belt I will be regulated to a great degree
by the operation of the escapement devices hereinbefore described, consisting of
the toothed wheels C and the reciprocating bars B, which will act like an escape-
ment to limit the speed of rotation of the drum. This speed of rotation is further
regulated through the action of the friction devices described and the cam G.
The parts may be so proportioned that when the weight is suspended entirely
from the toggle-joint connections, consisting of the links e, the friction devices
will clamp the suspending cord with sufficient force to check the descent of the
body, and in this case the cam G may be operated so as to make the descent as
slow or rapid as desired. Preferably, however, the parts should be so proportioned
that there will be a slow descent even when the cam G is not in use.
Our device is also preferably provided with crank arms K, having at their
outer ends handles K', adapted to be grasped by the hands of the user, and by
means of these arms the speed of descent may also be regulated, if desired. By
using the arms the device inay also be used as a hoisting apparatus. The ratchet

page_text: mechanism which regulates the speed of descent is such that it will create but
small friction when slowly operated.
The friction clamping devices, consisting of the rollers F and the levers by
which they are controlled, may be thrown entirely out of operation by properly
placing the cam G, and in this event by rotating the crank arms K the user may
hoist himself. The crank arms K may be arranged so as to be easily removed,
if desired.
The apparatus may thus be used for descending from any height, whether as a
fire-escape or as a matter of convenience, as in mining-shafts, wells, etc., and
also for carpenters, painters, and other workmen who have occasion to ascend or
descend to and from considerable elevations.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1st. The toggle levers el when arranged to support the weight and apply the
friction rollers to the rope C and combined with a device (such as the cam G)
for regulating the friction substantially as specified.
2nd. The bars B when connected by the lever D to move on opposite sides for
the purpose of limiting the speed of the drum CC substantially as specified.
1
0041
1900
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.