IMPROVEMENTS IN SAFETY CAGES OR APPARATUS FOR MINES." IMPROVEMENTS IN SAFETY CAGES or Apparatus FOR MINES
Year: 1858

page_text: LETTERS PATENT to Robert Aytoun, of Edinburgh, in the County of
Mid Lothian, North Britain, Writer to the Signet, for the Invention of
"IMPROVEMENTS IN SAFETY CAGES OR APPARATUS FOR MINES."
IMPROVEMENTS IN SAFETY CAGES or Apparatus FOR MINES."
Sealed the 25th June 1858, and dated the 10th February 1858.
PROVISIONAL SPECIFICATION left by the said Robert Aytoun at the
Office of the Commissioners of Patents, with his Petition, on the
10th February 1858.
I, ROBERT AYTOUN, of Edinburgh, in the County of Mid Lothian, North
Britain, Writer to the Signet, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SAFETY CAGES OR APPARATUS FOR MINES," to
be as follows, that is to say :-
This Invention relates to the arrangement and fitting up of mine cages or
the lifting and lowering apparatus employed in working mine shafts in such
manner as to obtain security from accidents in cases of fracture of the winding
rope or suspensory apparatus whilst the lifting and lowering of men and
materials is going on. In cages fitted up in this way the actual winding rope
or chain is connected at its lower end by a ring or hook, to which again is
attached a double chain, connected diagonally to the cage through the inter-
vention of certain spring clipping levers. On each opposite side of the cage
there is centred a duplex jamming or clipping lever set upon a fixed stud
centre, and disposed in opposite or reversed directions as regards each other;

page_text: it is to the shorter arm of each of these levers that the double chain already
referred to is attached, the two ends of the chain being attached respectively
to a lever; this end of each lever has also a spring attached to it, the other
ends of these springs being connected to fixed studs upon the cage. The
opposite longer arms of the jamming levers are formed with lateral projections
embracing the main vertical guides of the mine shaft, the relations of the parts
being such that so long as the jamming levers are kept in a horizontal position
the cage can work freely up and down the guides, but when they are thrown out
of the horizontal line, the lateral projections, upon the levers jam firmly upon
the guides on each face. The action of the arrangement is this,-so long as
the winding rope is in order, its tensional action, as induced by the weight of
the cage, retains the jamming levers at or about the horizontal line, so as to
clear them from their hold upon the shaft guides; when, however, the winding
rope fails, the reaction of the springs attached to the jamming levers brings
those levers into the proper angular position for jamming upon the guides,
thus holding the cage from falling. To prevent the jamming edges from
injuring the guides by indenting them too severely, the acting edges may be
somewhat rounded off, and to prevent the jamming action from wearing the
guides too much by the continual jamming of the lever holders at the top and
bottom of the shaft, the guides at these parts may be protected by sheet iron
or otherwise.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Aytoun in the Great Seal Patent Office on the 10th
August 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
AYTOUN, of Edinburgh, in the County of Mid Lothian, North Britain, Writer
to the Signet, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of February, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first-year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Robert Aytoun, Her special license, that I, the said Robert
Aytoun, my executors, administrators, and assigns, or such others as I, the
said Robert Aytoun, my executors, administrators, or assigns, should at
any time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make, use,

page_text: exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
SAPETY CAGES OR APPARATUS FOR MINES," upon the condition (amongst others)
that I, the said Robert Aytoun, 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 Robert Aytoun, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, 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 relates to the arrangement and fitting up of mine cages
or the lifting and lowering apparatus employed in working mine shafts, in
such manner as to obtain security from accidents in cases of fracture of the
winding rope or suspensory apparatus whilst the lifting and lowering of men
and materials is going on. In cages fitted up in this way the actual winding
rope or chain is connected at its lower end by a ring or hook, to which again
is attached a double chain, connected diagonally to the cage through the
intervention of certain spring clipping levers. On each opposite side of the
cage there is centred a duplex jamming or clipping lever set upon a fixed stud
centre, and disposed in opposite or reversed directions as regards each other;
it is to the shorter arm of each of these levers that the double chain already
referred to is attached, the two ends of the chain being attached respectively
to a lever; this end of each lever has also a spring attached to it; the other
ends of these springs being connected to fixed studs upon the cage. The
opposite longer arms of the jamming levers are formed with lateral projections
embracing the main vertical guides of the mine shaft, the relations of the
parts being such that so long as the jamming levers are kept in a horizontal
position the cage can work freely up and down the guides, but wlien they are
thrown out of the horizontal line, the lateral projections upon the levers jam
freely upon the guides on each face. The action of the arrangement is this,―
so long as the winding rope is in order, its tensional action, as induced by the
weight of the cage, retains the jamming levers at or about the horizontal line,
so as to clear them from their hold upon the shaft guides; when, however,
the winding rope fails, the reaction of the springs attached to the jamming
levers brings those levers into the proper angular position for jamming upon
the guides, thus holding the cage from falling. To prevent the jamming

page_text: edges from injuring the guides by indenting them too severely, the acting
edges may be somewhat rounded off, and to prevent the jamming action from
wearing the guides too much by the continual jamming of the lever holders at
the top and bottom of the shaft, the guides at these parts may be protected by
sheet iron or otherwise.
$
And in order that my said Invention may be properly understood, I shall
now proceed to describe the several Figures upon the explanatory Sheet of
Drawings which I have hereunto appended, for the purpose of showing certain
modifications under which my improvements may be judiciously carried out
in practice. In the illustrative Drawing my improvements are shown as
applied to a mining cage of the kind ordinarily used.
Figure 1 is an elevation or side view; Figure 2, an end view, taken at
right angles to Figure 1; and Figure 3 is a plan of one modification of the
improvements. According to this arrangement the lower part of the cage
consists of a rectangular framing A of timber, upon which the planks that form
the flooring B of the cage are laid. To each corner of the framing A, an iron
upright C is bolted, these are connected at the upper parts by corresponding
pieces of flat metal D, and at the ends by malleable iron tie rods. The cage
is covered in at the top by an angular metal roof, which is secured by bolts
and nuts to the vertical framing C, and transverse tie pieces D. The cage is
kept in a vertical position as regards the lower part by the guides E, and the
metal slides F that are bolted to the framing A. The upper part of the cage
is, however, guided on each side by a horizontal lever G, which is centred upon
a stud fixed to the transverse pieces D of the cage. The inner ends of the
levers G are made with laterally projecting cheek plates, the two projecting
parts forming a recess similar to that of the slides F, and in like manner made
to fit the vertical guides E. The two levers G are fitted to the framing D,
with their longer arms directed outwards to the angles of the framing, but in
opposite directions, as shown in the plan, Figure 3, on my illustrative Drawing.
A stop or projecting piece of metal H is attached to each of the transverse tie
pieces D, these stops project above the levers G, and serve to prevent them
from passing beyond the horizontal position in an upward direction. On the
under side of each lever, near its outer end, a staple is formed, through which
a strong band of vulcanised india-rubber I is passed, the ends of each spring
are secured by a bolt and washer to a bracket J, which is bolted to the up- $
right C. Each of the levers G has an eye at its outer end, to which is
connected one extremity of the chain K, which extends in a diagonal direction
across the cage, as shown in Figure 3, on my Drawing. Prior to attaching
the chain K to the levers G it is passed through the shackle L, which forms

page_text: the extremity of the hoisting chain or rope M; in this manner the cage is
suspended by the single chain K, which is made fast to the opposite diagonal
corners of the framing. While the hoisting chain or rope M, and the
connecting chain K are in perfect and working order, the cage travels freely
up and down the pit shaft, being kept in a vertical position by the slides F,
and those on the levers G, as they traverse up and down the guides E.
During this position of the several parts, the levers G press upwards against
the stops II, the levers being kept in a horizontal position by the weight of
the cage and the tension of the chain K; the springs I are at the same time
kept stretched to a certain extent by the horizontal position of the levers G.
When, however, the chain or rope M or the chain K breaks, or is otherwise
disconnected, the springs I contract to their ordinary length; the effect of this
is, that the longer arms of the levers G are drawn downwards and out of thic
horizontal line. This deviation of the levers causes the laterally projecting
cheeks of the sliding parts to press with much force upon the sides of the
guides E, and in this manner the levers G serve as jamming levers, and
instantly arrest the downward progress of the cage. In this modification of
my improvements the levers G are brought into action by the contraction of
the springs I, but it will be obvious that helical or blade springs may be used
in lieu of, or substituted for, the vulcanised india-rubber springs I. According
to another arrangement of my improvements the cage is fitted with duplex
jamming levers in lieu of the single lever arrangement, herein-before described,
that is to say, the upper part of the cage has a lever arrangement precisely
similar to that before described, but instead of the slides F that are shown in
Figures 1 and 2, on my illustrative Drawing, there is a second horizontal lever
fitted upon each side of the cage at the lower part. These lower levers are
made with projecting sliding parts, which traverse freely upon the vertical
guides, and they are centred upon laterally projecting studs in manner similar
to the levers G, herein-before described. To the outer ends of each of the
lower levers a rod is attached, which passes through snugs or eyes fitted to or
projecting from the framing of the cage. The upper extremities of these rods
project above the cage, and the central part of each rod has fast to it one end
of a helical spring, the other end of which is in contact with one of the snugs
through which the rod passes, or it may press against any other kind of fixed
5 stop. In this arrangement there are two suspending chains which are passed
through the shackle of the hoisting chain or rope, the two ends of one chain
being fastened to the upper levers, as herein-before described, and the other
two extremities being attached to the upper ends of the rods of the lower pair
of levers.
In this state of things, and while the suspending ropes or chains.

page_text: are perfect, the springs of the upper levers are stretched or extended, whilst
the helical springs of the lower levers are compressed against the fixed stops
upon the cage. Upon the breakage of either of the sustaining ropes or chains,
the contraction and extension of the springs throw the levers out of the hori-
zontal position, and both pairs are jammed against the sides of the vertical
guides, thereby instantly checking and stopping the descent of the cage. In
this arrangement, the two levers upon each side of the cage are disposed with
the extremities of their longer arms directed outwards, but in opposite direc-
tions, so that the duplex levers on one side of the cage extend to its opposite
diagonal corners, and in this manner the cage is supported from the four upper
corners or angles. According to another modification of the safety apparatus,
the two jamming levers are arranged upon each side of the cage with their
extremities in the same direction. The pair of levers upon the other side of
the cage are arranged in like manner, but with their ends extending outwards
in the opposite direction; so that the ends of the upper pair of levers may be
connected by a single chain, as in the arrangement shown in the accompanying
Drawing. Each pair of levers are connected to each other by a vertical rod so
that the two work in unison; and they are prevented from rising beyond the
horizontal line, by a stop against which the upper levers press when attached
to the suspending chain. The levers upon each side of the cage are brought
into action by a vulcanised india-rubber band spring, which is passed through
a link pendent from the under side of each of the upper levers, its ends being
fastened to a bracket projecting from the framing, or to the cage itself. Upon
the severance of the suspending chains or ropes, the contraction of the springs
causes the slides of the four levers to jam against the guides, and thus stop
the downward motion of the cage and its contents, so that by the use of one
or other of these arrangements, the falling of the cage from the fracture of tho
rope or chain may be prevented, and the sacrifice of life and property from
this cause be avoided.
my said
Having now described and particularly ascertained the nature of
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without de-
viating from the principles or main features of my Invention; but what I con-
sider to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent, is,―
First, the general arrangement and construction of safety cages for mining
purposes, as herein-before described.

page_text: Second, the system or mode of arresting the descent of mining cages, upon
the fracture or severance of the suspending or hoisting chain or rope, by
means of self-acting jamming levers, as herein-before described.
Third, the use and application to mining cages of levers which are made to
slide upon the vertical guides of the pit shaft, and thereby tend to keep the
cage in a vertical position during its ascent and descent, and to stop its falling
when the chain or rope breaks, as herein-before described.
Fourth, the system or mode of constructing safety cages for mining pur-
poses, in which two jamming levers are used for retarding and stopping the
descent of the cage upon the chain or rope breaking, or otherwise becoming
disconnected, the said levers being brought into action by means of springs, or
other mere equivalent therefor, as herein-before described, and shown in the
accompanying Drawing.
Fifth, the system or mode of constructing safety cages for mining purposes,
in which four jamming levers are used, arranged in pairs upon opposite sides of
the cage, and which levers are brought into action upon the severance of the
rope or chain, by means of band and helical springs, or other equivalents
therefor, as herein-before described.
Sixth, the system or mode of constructing safety cages for mining pur-
poses with duplex levers arranged upon opposite sides of the cage, the said
levers being connected together in pairs by means of vertical rods, each pair
being brought into action by a spring, or other equivalent therefor, as herein-
before described.
In witness whereof, I, the said Robert Aytoun, have hereunto set my
hand and seal, this Seventh day of August, One thousand eight hun-
dred and fifty-eight.
ROBERT AYTOUN. (L.S.)