AN IMPROVED SYSTEM AND ARRANGEMENT OF SAFETY APPARATUS APPLICABLE TO CAGES USED IN THE SHAFTS OF MINES AND HOISTS
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Edward Thomas Hughes at the
Office of the Commissioners of Patents, with his Petition, on the
12th January 1874.-A communication from abroad by Nicolas
Libotte, of Gilly, Belgium, Mechanical Engineer.
I, EDWARD THOMAS HUGHES, of the Firm of Hughes and Son, 123,
Chancery Lane, London, do hereby declare the nature of the said
Invention for "AN IMPROVED SYSTEM AND ARRANGEMENT OF SAFETY APPARATUS
APPLICABLE TO CAGES USED IN THE SHAFTS OF MINES AND HOISTS," a commu-
nication to me from abroard by Nicolas Libotte, of Gilly, Belgium,
Mechanical Engineer, to be as follows:
•
This improved safety apparatus is distinguished from all others by its
simplicity and facility of construction, for it is not operated as hitherto
by springs, which are susceptible of being relaxed or not acting, but by
the motion and weight of the cage, that is by all its acting force.
The safety apparatus consists of a framework divided in its length into
two frames or parts, each jointed to strong bolts or pins firmly fixed
cross frame at the top of the cage, so that the outer end of cach to the
frame can fall down when allowed to be acted upon by its own weight.

page_text: At each corner of the framework there is a strong bolt or rod placed
obliquely and terminated at the top by an eye or ring, to which is linked
one of the four chains, linked or connected to the block or bracket
attached to the end of the rope or cable of the winding engine.
On the sides of the frames near the joints which unite both parts
together there are two pairs of claws or grips projecting on the outside
of the cage, each pair when the safety apparatus or parachute is not in
action having between them a space a little larger than the guides at
the sides of the shaft or hole of the pit or hoist, so that the claws
slide up and down the length of the guides when there is no accident,
but when the rope or cable is broken the claws immediately claw or bite
into the guides and hold the cage.
To give more effect or power to the claws, the ends of the frames
which act as levers are mounted with weights, so that the claws so
penetrate deeply into the guides, and effectually stop or hold the cage if
the rope or cable should break. To compel the claws when they have
clawed into the guides to continue their seizure without relaxing there
is at each side a spring similar in shape to the catch or dog of a capstan,
one end of the springs being fixed or geared to the bosses of the claws,
and their other ends fixed to the frames to which the claws are jointed,
and thus any slipping or jerking of the frames and cage are prevented;
the two frames or halves of the frame work when the rope or cable
breaks or falls pass between the cross bars at the sides of the cage, which
bars in this case act as guides.
The results of this improved system and arrangement are, —
First. A complete security for the lives of the workmen and pre-
servation of the materials of the mine.
Secondly. The suppression of the high space required for the safety
apparatus of the old systems.
Thirdly. The capability of applying without difficulty this system of
stopping to all existing cages, it being only necessary to have in addition
a cross frame fixed above the top frame of the cage, the cross frame
forming the support to which the apparatus is jointed.
Fourthly. A great ecomony in repairs as all the parts are simply
bolted together, so that they can be removed and replaced with facility.

page_text: I can also modify the aforesaid system and apparatus,―
First. By arranging the claws in such a manner, that they have at the
top flat surfaces or slides, and at the bottom the sharp points forming
the claws or grips, so that when there is no accident the flat surfaces
run up and down the guides, but when the rope or cable breaks the
claws can claw or grip the guides, or the claws may be made as claws
only, and the running slides fixed to the wooden bars or beams at the
top of the cage.
Secondly. By placing spiral springs round the 4 ringed bolts to
which the apparatus is connected, 'the springs being compressed when
the two parts or halves of the apparatus are horizontal, that is in their
normal positions, but if from any cause the chains are relaxed the
springs extend and assist the claws to penetrate more and more into the
guides of the cage and prevent any relaxation of their scizure, and these
springs also prevent the too sudden shocks which might take place if the
cage went beyond the play allowed by the dog-shaped springs connected
to the bosses of the chains, and instead of the spiral springs round
the ringed rods or bolts springs made of plates of steel may be employed
for the same purpose.
Thirdly. I can also as required make the simple claws or the claws
and slides of steel and iron combined, according to the resistance of the
part or material against which the claws act.
Fourthly. By fixing near each end of the two parts or frames of the
apparatus an iron bar to be pulled by the workmen in the cage, to cause
the claws in case of need to act more quickly.
And Fifthly. By making the two parts or frames of the apparatus
slide or move between two guides, one inside and the other out, in order
to prevent them from deviating from their proper course.
To avoid the shocks which may take place in the cages suspended from
four bolts or rods, which shocks might bend the framework of the
apparatus and cage, I employ a double frame at the bottom of the cage,
one external and the other internal.
The external frame is connected to the vertical bars of the cage, and
the internal one which is moveable is connected by rods with the double
frame or apparatus to which the claws are jointed.

page_text: The lower moveable frame carries at the sides the iron slides, which
run up and down the guides, so that though the vertical movements of
the cage shall be perfectly free, horizontal shaking will be entirely
prevented, thus assuring the proper working of the apparatus in case the
rope or cable breaks. By these means the moveable frames may be very
light, as there can be no shock in consequence of the play of springs
connected to the bosses of the claws having no bad effect, and it is
evident that these modifications can be applied to all existing cages.