AN IMPROVED HOISTING MACHINE
Year: 1870

page_text: LETTERS PATENT to James Jennings McComb, of Liverpool, in the
County of Lancaster, Gentleman, for the Invention of "AN IMPROVED
HOISTING MACHINE."-A communication from abroad by Henry Reedy,
of Cincinnati, in the State of Ohio, United States of America.
Sealed the 1st November 1870, and dated the 2nd May 1870.
PROVISIONAL SPECIFICATION left by the said James Jennings McComb
at the Office of the Commissioners of Patents, with his Petition, on
the 2nd May 1870.
I, JAMES JENNINGS MCCOMB, of Liverpool, in the County of Lancaster,
Gentleman, do hereby declare the nature of the said Invention for "AN
IMPROVED HOISTING MACHINE," to be as follows:-
This Invention relates to a mode of supporting the platform of a
hoisting machine upon the mid length of a single rope whose two ends
after passing upward and over two sheaves or pulleys are attached to
suitable weights, which not only counterbalance the platform but also
compel the rope to hug said sheaves very closely, so that when the latter
are rotated in either direction the platform will be elevated or depressed,
thereby dispensing with the ordinary drum upon which the hoisting rope
is usually wound.

page_text: The platform is fitted with side stiles which are stiffened by a cross
piece and bracings, thus forming a rigid frame. The platform frame
slides in vertical guides which carry an overhead framing. On this
framing is mounted a horizontal pulley shaft, over the pulleys of which
the ends of the suspending rope pass. The weights which are attached
to the ends of this rope slide in vertical guides, and the rope in passing
under the platform bears against two small rollers, carried by the
platform, which serve to prevent the rope from chafing. The pulley
shaft is connected by gearing to a driving shaft which carries a large
driving pulley for setting the apparatus in motion and raising and
lowering the platform with its load. For arresting the descent and
ascent of the platform, and to maintain it at any desired elevation, a
break arrangement is provided. Below the driving shaft and parallel
therewith is a break shaft, which has keyed to it a ratchet wheel, a
break piece, and a lever, the latter having attached to its free end a cord
by which it is worked. Mounted above the ratchet wheel is a pawl
fitted with a counterbalance weight, and carrying at its other end a rope
for putting the pawl into action. When it is desired to arrest the
progress of the platform the cord of the lever is pulled by the operator,
so as to cause the brake piece to press against the periphery of the driving
pulley and instantly check the rotation of the latter and its accom-
panying elevating devices, and by drawing on the pawl rope the pawl
will engage with the teeth of the ratchet wheel so as to lock it. When
the brake is in this condition the platform can be safely maintained at
any position for an indefinite length of time. For small hoisting
machines, dumb waiters, and the like, a single counterbalance sheave and
rope may be employed, the latter being attached to the mid length of
the platform frame.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Jennings McComb in the Great Seal Patent 30
Office on the 2nd November 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
JENNINGS MCCOMB, of Liverpool, in the County of Lancaster, Gentleman,
send greeting.

page_text: our Lord One thousand eight hundred and seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said James Jennings McComb, Her special licence
that I, the said James Jennings McComb, my executors, administrators,
and assigns, or such others as I, the said James Jennings McComb, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED HOISTING
MACHINE," being a communication to me from abroad by Henry Reedy,
of Cincinnati, in the State of Ohio, United States of America, upon the
condition (amongst others) that I, the said James Jennings McComb, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said James Jennings McComb, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawing here-
unto annexed, and to the letters and figures marked thereon (that is to
say):
:-
This Invention relates to a mode of supporting the platform of a
hoisting machine upon a rope whose ends after passing upward and over
two sheaves or pulleys are attached to suitable weights, which not only
counterbalance the platform but also compel the rope to hug the sheaves
very closely, so that when the latter are rotated in either direction
the platform will be elevated or depressed, as the case may be, thereby
dispensing with the ordinary drum upon which the hoisting rope is
usually wound.
In the accompanying Drawing, Fig. 1 shews in front elevation a hoist
constructed according to this Invention, and Fig. 2 is a sectional
elevation of the same taken in the line 1, 2, of Fig. 1.
A, A, A', A', are standards which serve as guides to the suspended
platform B and to its counterweights. The mechanical devices for

page_text: operating the hoist are mounted between standards A2, A3, and A, firmly
secured to the upper floor and roof of the building in which the appa-
ratus is erected. The platform B is carried by a gallows frame B¹, the
side bars of which are furnished with guide pieces 6 which run over the
guides of the standards A, and the platform is made fast to its frame by
means of metal struts and tie rods . C is a transverse shaft mounted
in suitable bearings carried by the standards A2, A3, and to it is keyed a
pair of sheaves or pulleys C¹; D is a rope which passes under the plat-
form B and is led upwards and over the sheaves C', and to the pendent
ends of this rope counterweights D¹ are attached, which weights run in
guides formed by the standards A'. To protect the rope D from fraying
guide pulleys are fitted to the under side of the platform B, by which
arrangement an equality of tension throughout the length of the rope is
always maintained; but if desired the rope may be fixed to the platform,
or two ropes of half the length of the one rope may be attached to
opposite sides of the platform. In order to ensure a proper bite of the
rope or ropes upon the sheaves C¹ it is proposed to serve the ropes with
spun yarn, which will prevent the ropes from slipping in the sheaves.
The hoist is operated through the rotation of the shaft C, and to effect
this rotation there is keyed to the end of the shaft a spur wheel C² which
gears into a pinion E on the short shaft E¹ which carries the hauling
pulley or main sheave wheel E². This sheave receives motion from a
rope E³, which runs in either direction, actuated by manual or steam
power. For arresting the descent and ascent of the platform, and to
maintain it at any desired elevation, a break arrangement is employed
which consists of a rock lever F which carries at one end a rack F', and
is weighted at its other end. The weighted end of this lever also carries a
spring or clastic friction block F which is intended to bear against and
Above this lever
arrest the motion of the driving sheave or pulley E².
is mounted a counterweighted pawl G, which pawl is intended to take
into the rack F and hold the friction block in contact with the driving
pulley. Pendent from the weighted lever F is a cord f, and from the
pawl G depends a similar cord 9, which cords are led down and are
brought within reach of the attendant, who may be situated on the floor
or staging H or at a lower level. When the hoist is required to be set
in motion the attendant pulls upon the cord f so as to disengage the
pawl from the rack, and that being effected he lets go the rope, thereby
leaving the lever free to fall and put the break block out of contact
with the driving pulley. Motion being now given to the pulley through

page_text: its rope Es in the desired direction rotary motion will be communicated
through the spur gearing to the shaft C, and the sheaves C¹ will be
caused to lift or lower the platform as desired. Supposing the load
which has been placed on the platform to have attained the desired
elevation or depression the attendant will then pull the cords ƒ and g,
and thereby draw down the rack with its pawl and lift the friction block
into contact with the driving pulley. The pawl will by this act of the
attendant hold the friction block in contact with the pulley, and thereby
arrest its motion and secure the hoist in the position it has attained.
From the above description it will be understood that as the rope which
carries the platform also supports the counterbalance weights several
ropes and pulleys otherwise required will be dispensed with, and the
amount of friction arising from their use will be avoided. It will also
be seen that as the hoisting apparatus has no drum for the rope to wind
upon there is no danger of the coils of rope crowding and riding one
upon another. For small hoisting machines, dumb waiters, and the like,
a single counterbalance weight, sheave, and rope may be employed, this
latter being attached to the mid length of the platform.
Having now set forth the nature of my Invention of an improved
hoisting machine, as communicated to me by my foreign correspondent,
and explained the manner of carrying the same into effect, I wish it
to be understood that under the above in part recited Letters Patent
I claim,―
First. Suspending the platform of hoisting machines from a counter-
balance rope or ropes pendent from sheaves or pulleys which are mounted
and driven in the manner and for the purpose above described.
Second. The arrangement above described for arresting the descent
and ascent of the platform, and for maintaining it at any desired
clevation.
In witness whereof, I, the said James Jennings McComb, have
hereunto set my hand and seal, the Twenty-ninth day of October,