IMPROVEMENTS IN SAFETY APPARATUS FOR MINE CAGES AND OTHER ELEVATORS
Year: 1875

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
" IMPROVEMENTS IN SAFETY APPARATUS FOR MINE CAGES AND OTHER
ELEVATORS." -A communication from abroad by Henry Carlile and
W. R. E. Elliott, both of Steubenville, in the County of Jefferson,
PROVISIONAL SPECIFICATION left by the said Alexander Melvillė
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 21st December 1875.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN SAFETY APPARATUS FOR MINE
CAGES AND OTHER ELEVATORS," to be as follows:-
:―
ر
The Invention consists in the employment of novel means in a
miner's cage or other elevator for the purpose of preventing the sudden
fall of the same on a break of the rope or other hoisting apparatus,

page_text: The cage or sliding platform in which men, merchandise, or material
may be raised or lowered is provided with grooves, which embrace guides
on the vertical framing. The cage is attached by cords to a central
lifting rope that may pass through the top of frame.
Instead of the usual clamps for locking the cage or platform to the
guides when the rope breaks I use peculiarly constructed bevel clamps,
each of which has parallel bearing surfaces which are placed obliquely
to the levers, one within the other, and pivoted crosswise together.
Each lever thus bites on both sides of the guides.
A spring whose slot works over the pivot extends out from the guide
before-mentioned, and serves to hold the levers loosely to the guides,
while the distance between the opposite working faces of each lever is
sufficiently great to allow them play on the pivot, so that when turned
in one direction they will slide smoothly and unobstructedly on the
guides, but when turned in the other will seize them with a vice-like
grasp, and at once prevent a downward movement of the cage or
platform. These levers may be connected in various ways with the
platform, so that its weight will cause them to bite upon the guides.
I esteem the best means for opening and clamping the levers to
consist in the following devices:-I attach the end of each long arm to
the platform by a cord, so long that when taut the clamps will bit upon
the guides, and when slacked they will be out of frictional contact with
them. The end of the short arm of one lever is connected by a rigid
strap with the end of the long arm of another lever, the end of its
short arm being connected by a cord with the lift rope. I also place
under the end of the long arm of said lever a spring of merely sufficient
tension when unresisted to throw the working faces of the clamps
instantaneously into contact with the guides. As soon as the lift rope
breaks the spring performs its function, and then the weight of the
platform and its contents acts through the cords to hold the clamps
firmly and immovably against the guides. As the lift rope rises the
short end of the lever rises, the long end is borne, down, and by means
of the strap in connection therewith the clamps are ungripped and
enabled to slide with the platform.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 9th June 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by. Her
Letters Patent, bearing date the Twenty-first day of December, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alexander Melville Clark,
Her special license, that I, the said Alexander Melville Clark, my
executors, administrators, and assigns, or such others as I, the said
Alexander Melville Clark, 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 "Improvements in SAFETY APPARATUS FOR MINE
CAGES AND OTHER ELEVATORS," a communication to me from abroad by
Henry Carlile and W. R. E. Elliott, both of Steubenville, in the County
of Jefferson, and State of Ohio, United States of America, upon the
condition (amongst others) that I, the said Alexander Melville Clark,
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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alexander Melville Clark, 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 accom-
panying Sheet of Drawings, and to the letters and figures marked
thereon, that is to say :-
This Invention consists in the employment of novel means in a

page_text: miner's cage or other elevator for the purpose of preventing the sudden
fall of the same on a break of the rope or other hoisting apparatus.
Figure 1 is a perspective, and Fig. 2 a series of detail views in
elevation. These means will first be fully described in connection with
all that is necessary to a full understanding thereof, and then pointed
out in the claims.
A represents the cage or sliding platform in which men, merchandise,
or material may be raised and lowered. It is provided with grooves
a, a, which embrace the guides b, b, of the frame B. The cage is
attached by cords C, C, C, C, to a central lifting rope D that may pass
through the top of frame.
Instead of the usual clamps for locking the cage or platform to the
guides b, b, when the rope breaks I use the peculiarly constructed bevel
clamps E, E, each of which has parallel bearing surfaces e, e, which
are placed obliquely to the levers, one within the other, and pivoted 1
crosswise together. Each lever thus bites on both sides of the guides.
A spring F, whose slot of works over the pivot e', extends out from
the guide b, and serves to hold the levers loosely to the guides b, b,
while the distance between the opposite working faces of each lever is
sufficiently great to allow them play on the pivot e¹, so that when turned
in one direction they will slide smoothly and unobstructedly on the
guides, but when turned in the other will seize them with vice-like
grasp, and at once prevent a downward movement of the cage or
platform. These levers may be connected in various ways with the
platform, so that its weight will cause them to bite upon the guides.
I esteem the best means for opening and clamping the levers to
consist in the following devices -I attach the end of each long arm to
the platform at g by a cord G, so long that when taut the clamps will
bite upon the guides b, and when slacked they will be out of frictional
contact with them. The end of the short arm of one lever is con-
nected by a rigid strap H, with the end of the long arm of the lever I,
which is itself pivoted at i, and has the end of its short arm connected
by a cord J with the lift rope.. I also place under the end of the long
arm of lever I a spring K, of merely sufficient tension when unresisted
to throw the working faces of the clamps E, E, instantaneously into
contact with the guides b, b. As soon as the lift rope breaks the spring
c

page_text: K performs its function, and then the weight of the platform and its
contents acts through the cords G, G, to hold the clamps firmly and
immovably against the guides. As the lift rope rises the short end of
lever I rises, the long end is borne down, and by means of the con-
nection H the grip of the clamps is released, and they are enabled to
slide with the platform.
Having described the nature of the said Invention, and the manner
of performing the same, I would observe that I am aware that
automatic clamps to bite upon the sides of guides and arrest the
elevator when a rope or lifting device breaks is not broadly new,
what I claim as the Invention to be protected by the herein-before in
part recited Letters Patent is,-
°
C
but
1st. The combination, with guides b, b, of two crossed and pivoted
clamp levers E, E, having the parallel working faces e, e, operated
in the manner and for the purpose specified.
2nd. The combination, with lift rope of the lever I connected there-
with at its short end, and with the short arm of clamp lever at its long.
end, thus enabling the grip clamps to be released in the manner set
forth..
3rd. The combination, with arm of lever I, having a subjacent
spring, and connected by a rigid strap with the short arm of lever
clamp E of the cage or platform having cords G, G, attaching it to the
long arms of levers E, E, thus enabling the latter to be clamped upon
the guide in the manner specified.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Ninth day of June, in
the year of our Lord One thousand eight hundred and seventy-
siz