AN IMPROVED SAFETY APPARATUS APPLICABLE TO CAGES USED IN THE SHAFTS OF MINEs and HOISTS
Year: 1875

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills, of the Firm of
Harris and Mills, of 23, Southampton Buildings, in the County of
Middlesex, Patent Agent, for the Invention of "AN IMPROVED
SAFETY APPARATUS APPLICABLE TO CAGES USED IN THE SHAFTS OF MINEs and
HOISTS." A communication from abroad by Nicolas Libotte, of
Gilly, near Charleroi, in the Kingdom of Belgium, Mechanical
Engineer.
Scaled the 18th February 1876, and dated the 27th August 1875.
PROVISIONAL SPECIFICATION left by the said Benjamin Joseph
Barnard Mills at the Office of the Commissioners of Patents,
with his Petition, on the 27th August 1875.
I, BENJAMIN JOSEPH BARNARD MILLS, of the Firm of Harris and
Mills, of 23, Southampton Buildings, in the County of Middlesex,
Patent Agent, do hereby declare the nature of the said Invention for
"AN IMPROVED SAFETY APPARATUS APPLICABLE TO CAGES USED IN THE SHAFTS OF
MINES AND HOISTS," a communication to me from abroad by Nicolas

page_text: Libotte, of Gilly, near Charleroi, in the Kingdom of Belgium,
Mechanical Engineer, to be as follows :=
The improved apparatus, instead of causing the more or less sudden
stoppage of the cage as heretofore by the clutches penetrating into
upright guides for the cage, effects the arrest of the cage by means of
wedges forced between their guides and the upright guides.
The cage is provided at each of its four corners with a bolt passing
through the framing and having a ring between which and a suitable
stop a helical or other spring is placed. These bolts are connected as
heretofore to short chains which are connected to a central ring or eye
by which the cage is connected to the main chain or rope. These bolts
are each connected by pin-joint to a lever fixed on an axis of motion, on
which axis is also fixed a shorter lever, to the outer end of which a
sliding wedge is pin-jointed. These wedges slide in guides fixed to the
cage, and the faces of the guides are inclined to correspond with the
backs of the wedges, whilst the fronts of the wedges or those parts
which act against the upright guides for the cage are toothed or
roughened over their entire surfaces. The wedge guides have side
flanges to retain the wedges in position. By these means, supposing
the main chain or rope should break, the springs would act upon the
levers to force the wedge in between the wedge guides and the guides
for the cage, and thus cause the arrest of the cage.
By penetrating into the woody body of the cage guides the friction is
increased by the toothed or roughened surfaces of the wedges, and
consequent on the peculiar action of the wedges the arrest of the cage
becomes prompter, surer, and more perfect, and in case of the chain or
rope breaking the fall of the cage is prevented.
The simplicity with which the motion of the operating springs is'
transmitted to the sliding wedges is worthy of attention; whilst by the
peculiar construction of the apparatus the cage escapes the shocks to
which it would be otherwise liable.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Benjamin Joseph Barnard Mills in the Great
Seal Patent Office on the 26th February 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
JOSEPH BARNARD MILLS, of the Firm of Harris and Mills, of 23, South-
ampton Buildings, in the County of Middlesex, Patent Agent, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of August, 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
successors, give and grant unto me, the said Benjamin Joseph Barnard
Mills, Her special license that I, the said Benjamin Joseph Barnard
Mills, my executors, administrators, and assigns, or such others as
I, the said Benjamin Joseph Barnard Mills, my executors, admini-
strators, and assigns, should at any timé 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 SAFETY
APPARATUS APPLICABLE TO CAGES USED IN THE SHAFTS OF MINES AND HOISTS,"
communicated to me from abroad by Nicolas Libotte, of Gilly, near
Charleroi, in the Kingdom of Belgium, Mechanical Engineer, upon the
condition (amongst others) that I, the said Benjamin Joseph Barnard
Mills, 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 Benjamin Joseph Barnard Mills,
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 thereof, reference being
had to the Drawings hereunto annexed, and to the letters and figures
marked thereon, that is to say :—
The improved safety apparatus instead of causing the more or less

page_text: sudden stoppage of the cage as heretofore by clutches penetrating into
_ upright guides for the cage-effects the-arrest-of-the-cage by means of
wedges forced between their guides and the said upright guides..
Figures 1 and 2 of the accompanying Drawings represent two
positions of the improved safety apparatus applied to a cage; and
Figure 3 represents a plan thereof showing clearly the various parts.
F, F, represent the guides for the wedges above mentioned. These
guides are fixed rigidly to the upper framing N of the cage to which
they are bolted. It will be seen that the faces of these wedges turned
towards their guides F are inclined with respect to the latter, and that
the guides are provided laterally with checks or flanges to enclose the
sliding wedges E which slide therein, and by the binding action
established between the guides F, the sliding wedges E, and the upright
guides M the arrest of the cage is effected in the event of the breakage
of the, suspending tackle. These sliding wedges leave their friction
surfaces towards the upright guides M toothed upon their entire surface.
By penetrating into the woody body of the guides this toothed
surface multiplies the friction, and by reason of the peculiar action of
the wedges E in the guides F the arrest of the cage is rendered more
gradual, more perfect, and more certain than by the modes heretofore
adopted. Also by these means in case of the suspending tackle becoming
broken the descent of the cage to the bottom of the pit is rendered
impossible.
The simplicity of the means by which the acting springs are caused to
operate the sliding wedges is a valuable feature. It will be seen by
inspecting the various Figures that these sliding wedges E are connected
at their lower ends by bolts Q to short levers C fixed on axes of motion H
which are mounted in bearings J fixed to the upper framing N of the
cage. The axes H are partly rotated in their bearings by means of long
levers B, which through the intervention of a cross bar P connecting
each pair together are operated by the motive power of helical springs A.
The application of these helical springs A (which resemble those
employed in railway carriages), which when compressed represent a
considerable motive power, is an important feature of the present
Invention. They insure, so to say, the instantaneous grip of the
wedges E on the upright guides M, which grip is progressively increased
by the weight of the cage and its contents,

page_text: The extended frictional surface afforded by these wedges insures the
arrest of the cage even with small pressure. This advantage is the
more valuable as it aids at the same time in the preservation of
the upright guides M which other forms of safety apparatus have a
tendency to injure.
The peculiar proportions of the levers B and C enable the sliding
wedges E in their normal condition to be retained at such a distance
from the upright guides M as may be judged convenient to prevent the
accidental action of the stopping apparatus.
D represents the links to which the small suspending chains of the
cage are attached; G, G, represent the pins or bolts connecting the
levers B to the links D.
I, I, represent guides acting in conjunction with the upright
guide M.
K, K, represent plates against which the volute springs act.
L, L, represent parts of the cage; 0, 0, represent the suspending
block and small chains.
R, R, represent angle irons to which the roof W of the cage is fixed,
and which serve at the same time to limit the action of the levers B.
S, S, represent bolts fixed to the cross bar P to guide the volute
springs A, and at the same time limit the action of the parts; T, T,
represent guards or covers to prevent any foreign matters entering
between the wedges E and their guides F.
Having thus described the nature of the said Invention, and the mode
in which the same may be carried into effect, I would have it under-
stood that what I claim is, the peculiar.construction, arrangement, and
mode of operation of safety apparatus applicable to cages used in the
shafts of mines and hoists, substantially as herein shown and described.
In witness whereof, I, the said Benjamin Joseph Barnard Mills,
have hereunto set my hand and seal, this Twenty-sixth day of
February, in the year of our Lord One thousand eight hundred
and seventy-six.