IMPROVEMENTS IN PREVENTING ACCIDENTS IN THE SHAFTS OF MINES, AND PROVISIONAL SPECIFICATIONINERY OR APPARATUS EMPLOYED THEREFOR
Year: 1873

page_text: LETTERS PATENT to David Inglis Urquhart, of Leith, in the County
of Mid Lothian, North Britain, Iron Merchant, for the Invention of
"IMPROVEMENTS IN PREVENTING ACCIDENTS IN THE SHAFTS OF MINES, AND
PROVISIONAL SPECIFICATION left by the said David Inglis Urquhart
at the Office of the Commissioners of Patents, with his Petition,
on the 10th July 1873.
I, DAVID INGLIS URQUHART, of Leith, in the County of Mid Lothian,
North Britain, Iron Merchant, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PREVENTING ACCIDENTS IN THE SHAFTS OF
MINES, AND IN THE MACHINERY OR APPARATUS EMPLOYED THEREFOR," to be as
follows, that is to say :-
This Invention which relates to improvements in the arrangement or
construction of mine cages has for its object to prevent the falling of the
cage in the shaft at a time when the winding rope or chain by which it
is suspended breaks.

page_text: Under the first modification of the Invention the cage proper is
situated within an outer cage or framing, and both are suspended from
the winding rope or chain. The inner cage is of less height than the
outer one, and when suspended is situated close up against or near to the
upper part of the outer cage, so that there is a free space left between
the bottoms of the two cages. Several levers are jointed to the upper
part of the outer cage, the inner and longer ends of which are attached
to the inner cage, and at their outer ends eyes, jaws, or openings are
formed which surround a corresponding number of ropes or rods stretched
tight; these ropes or rods extend throughout the entire length of the
shaft in which the cage operates. When the winding chain or rope
breaks the inner cage falls on the outer one through the free space
between the bottoms of each, and its weight acting upon the levers
herein-before described pulls them downwards, thereby causing the eyes,
jaws, or openings at their outer ends to seize on the tightly stretched
ropes or chains, the result of which is that the cage becomes instantly
fixed in the shaft and is thereby prevented from falling.
Under a second modification in place of employing one cage inside
another a weight placed in the upper part of the cage and connected to
the levers herein-before described may be substituted for the inner cage;
this acts upon the levers and causes them to seize upon the stretched
ropes or chains when the winding rope or chain breaks.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Inglis Urquhart in the Great Seal Patent
Office on the 9th January 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
INGLIS URQUHART, of Leith, in the County of Mid Lothian, North
Britain, Iron Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of July, in the year
of our Lord One thousand eight hundred and seventy-three, in the 37th
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said David Inglis Urquhart, Her special license.

page_text: that I, the said. David Inglis Urquhart, my executors, administrators,
and assigns, or such others as I, the said David Inglis Urquhart,
my executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times thereafter,
3 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 PREVENTING ACCIDENTS IN THE SHAFTS OF MINES, AND IN THE
MACHINERY OR APPARATUS EMPLOYED THEREFOR," upon the condition (amongst
others) that I, the said David Inglis Urquhart, by an instrument in
writing under my hand and seal, 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 David Inglis Urquhart, do hereby
declare the nature of my 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 accompanying
Drawings, and to the letters and figures marked thereon, that is to
say :-
My said Invention which relates to improvements in the arrangement
or construction of mine cages has for its object to prevent the falling
of the cage in the shaft at a time when the winding rope or chain by
which it is suspended breaks.
Under the first modification of the Invention the cage proper is
situated within an outer cage or framing, and both are suspended from
the winding rope or chain. The inner cage is of less height than the
outer one, and when suspended is situated close up against or near to
the upper part of the outer cage so that there is a free space left between
the bottoms of the two cages; levers are jointed to the upper part of the
outer cage, the inner and longer ends of which are attached to the inner
cage, and at their outer ends eyes, jaws, or openings are formed which
surround a corresponding number of ropes or rods stretched tight; these
ropes or rods extend throughout the entire length of the shaft in which
the cage operates. When the winding chain or rope breaks the inner
cage falls in the outer one through the free space between the bottoms

page_text: of each, and its weight acting upon the levers herein-before described
pulls them downwards, thereby causing the eyes, jaws, or openings at
their outer ends to seize on the tightly stretched ropes or chains, the
result of which is that the cage becomes instantly fixed in the shaft and
is thereby prevented from falling.
Under a second modification in place of employing one cage inside
another a weight placed in the upper part of the cage and connected to
the levers herein-before described may be substituted for the inner cage;
this acts upon the levers and causes them to seize upon the stretched
ropes or chains when the winding rope or chain breaks.
And in order that my said Invention may be properly understood I
now proceed more particularly to set forth the system, mode, or manner
in or under which the same is or may be used or practically carried
into effect, that is to say:-
On Sheet 1 of the Drawings hereunto appended Figure 1 is a vertical 1
section of an improved cage as constructed according to the first modifi-
cation of my said Invention; Figure 2 is a plan of Figure 1; and
Figure 3 is another vertical section at right angles to Figure 1.
The exterior cage of the apparatus is marked A, and within which the
smaller cage B is situated, both of these cages being suspended from the 2
winding rope and chain C, passing over the pulley or drum X; the outer
cage is secured to the chain C by means of a link D, which passing
through a hole formed in the upper part of the framework of the cage A
terminates in a collar, upon which the cage finds support; to an eye
formed at the lower extremity of the link D there is attached a chain 2
terminating in a cross link E, to which the links F are also attached,
these being again connected to the forked levers G by pins H; from the
pins H the inner cage B is suspended by means of links and eye bolts I
secured to the upper part of the cage B; to prevent undue oscillation or
vibration in ascending or descending guide pieces J sliding upon the a
ordinary guides K may be secured to the side framing of the inner
cage B; the forked levers G are secured to the outer cage A in brackets
L, shewn more particularly at Figure 2; upon these brackets long bosses
are formed, through which and also through the forks of the levers G
pins M are passed, and upon the pins M the levers G are free to move,
these pins M constituting the fulcra of the levers G; at the outer
extremities of the levers G eyes or bosses N are arranged surrounding a

page_text: corresponding number of ropes O (but preferably metallic rods), stretched
tightly the entire length of the shaft; the outer cage A. is guided in the
ordinary manner by brackets P sliding on the guides K.
'
The action of the mechanism when the winding rope or chain C
breaks in the course of ascent or descent is as follows:-The inner
cage B being by the breaking of the rope or chain C deprived of its
support falls through the free space Q situated between the bottoms of
the exterior and interior cages A and B, and pulls downwards with it in
its descent the inner extremity of the levers G, which moving on the
pins M are thrown into the position indicated by the dotted lines,
Figure 1, and in which position the eyes or bosses formed on the outer
extremities of the levers G grip the ropes or rods O and thereby prevent
the falling of the cage.
If desired the mechanism may at any time be rendered inactive by
introducing into the free space Q and between the bottoms of the interior
and exterior cages blocks, screws, or other obstructions that will prevent
the inner cage B from falling on the breaking of the chain; or the
levers G may be held up by introducing wedges or blocks between them
and the upper part of the outer cage.
Sheet 2 of the appended Sheets of Drawings contains a modification
of my said Invention, of which Figures 1 and 3 are vertical sections at
right angles to each other; and Figure 2, a plan. By this arrangement
(which is in all other respects similar to the modification herein-before
described) the inner cage is dispensed with and weights R are
substituted therefor, which hang from the inner extremities of the
branched levers G.
In the event of the winding rope or chain C breaking the effect pro-
duced is the same as that obtained by the use of the inner cage. The
falling weights by depressing the inner extremities of the levers G throw
them into the position indicated by the dotted lines, which as has been
already set forth in reference to the first modification produces the effect
of arresting the fall of the cage. Under this Invention the ordinary
guides K may be dispensed with, the ropes or rods O acting as their
substitutes.
Having now described and particularly ascertained the nature of my
said Invention, and the system, mode, or manner in or under which the

page_text: same is or may be used or practically carried into effect, I would observe
in conclusion that what I consider to be novel and original and therefore
claim as the Invention secured to me by the herein-before in part
recited Letters Patent is, the arrangement and construction of mechanism
for preventing the falling of cages in shafts, and consisting of levers
attached to the cage and acted upon by an inner cage or by weights,
which levers in the event of the winding chain or rope breaking grip or
seize tightly stretched ropes or rods in the shaft, as herein-before
described, or any mere modification thereof.
In witness whereof, I, the said David Inglis Urquhart, have here-
unto set my hand and seal, this Seventh day of January, One
thousand eight hundred and seventy-four.
DAVID INGLIS URQUHART. (L.S.)