IMPROVEMENTS IN MINERS' SAFETY CAGES, LIFTS, AND OTHER LIKE HOISTING APPARATUS
Year: 1868

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN MINERS' SAFETY CAGES, LIFTS, AND OTHER LIKE
HOISTING APPARATUS." - A communication from abroad by John
Vaughan Merrick and William Henry Merrick, both of Philadelphia,
Pennsylvania, in the United States of America, Engineers.
Sealed the 10th November 1868, and dated the 12th June 1868.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 12th June 1868.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
3 of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN MINERS' SAFETY CAGES, LIFTS, AND OTHER
LIKE HOISTING APPARATUS," a communication to me from abroad by John
Vaughan Merrick and William Henry Merrick, both of Philadelphia,
Pennsylvania, in the United States of America, Engineers, to be as
> follows:-
This Invention relates to certain peculiar combinations or arrange-

page_text: ments of mechanism for arresting miners' safety cages, lifts, or other
like hoisting apparatus in their descent when the hoisting rope or
chain breaks, and consists essentially in bringing into action the
arresting mechanism of the cage or lift by means of the counterweight
of the said cage or lift in substitution for springs, which are too un-
certain in their action, and are too liable to fracture when brought
suddenly into action to be safely relied upon for the purpose re-
ferred to.
According to one mode of carrying out this Invention a rack is
secured to each of the side frames, and a pair of safety levers are carried
horizontally on centres in the top cross bar or bars of the cage. The
outer and short arms of these levers are serrated to correspond to the
racks, and the inner ends of the long arms are connected by links to the
hoisting rope or chain, whilst the short arms are connected by cords or
chains passing over guide pulleys to the counterweight of the cage or
lift. So long as the weight of the cage is on the hoisting rope or chain
the safety levers will be held up and their toothed ends kept clear of
the racks, but should the hoisting rope or chain break then the gravity
of the descending cage or lift acting in opposition to that of the
counterweight will cause the short ends of the safety levers to be lifted
and engaged into the rack teeth, thereby at once arresting the further
descent of the cage or lift.
According to a second modification toothed horizontal safety slides
are substituted for the safety levers, such slides being respectively
connected to the lower arms of two double bell-crank or T-shaped levers
working on centres in the top cross bar or bars of the cage. The inner
or contiguous ends of the horizontal arms of these T-shaped levers are
connected by links to the hoisting rope or chain, whilst their outer or
opposite ends are connected by other links with the counterweight
rope or chain.
The toothed ends of the slides work through metal
guides attached to the corners of the cage, and are retained clear of
the racks until a breakage of the hoisting rope or chain occurs, where-
upon
the action of the cage and counterweight upon the outer ends of
the horizontal arms of the T-shaped levers forces the safety slides
outwards and causes their teeth to engage with the teeth of the racks,
thereby arresting the descent of the cage or lift.
According to a third modification applicable where wire rope guides
are used safety levers arranged and actuated in a manner similar to

page_text: those described in the first modification are employed, but in lieu of
being serrated or toothed at their outer ends they are each provided at
that part with a wedge which wedges on the breakage of the hoisting
rope or chain, enter the lower expanded mouths of the guide holes in
the cage through which the wire guide ropes pass, and nip the said
guide ropes with sufficient force to arrest the descent of the cage or
lift.
SPECIFICATION in pursuance of the conditions of the Lettere Patent,
-
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 11th December 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JoHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of June, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Henry Johnson, Her special
license that I, the said John Henry Johuson, my executors, adminis-
trators, and assigns, or such others as I, the said John Henry
Johnson, my executors, administrators, or 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 MINERS' SAFETY CAGES, LIFTS, AND OTHER LIKE HOISTING
APPARATUS," a communication from abroad by John Vaughan Merrick
and William Henry Merrick, both of Philadelphia, Pennsylvania, in. tlio
United States of America, Engineers, upon the condition (amongst
others) that I, the said John Henry Johnson, my executors or ad-
ministrators, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said In-
vention, 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.

page_text: NOW KNOW YE, that I, the said John Henry Johnson, 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 Drawings, and to the letters and figures marked thercon, that
is to say:
The said Invention relates to certain peculiar combinations or arrange-
ments of mechanism for arresting miners' safety cages, lifts, or other
like hoisting apparatus in their descent when the hoisting rope or chain
breaks, and consists essentially in bringing into action the arresting
mechanism of the cage or lift by means of a counterweight in connection
with the mechanism by which the cage or lift is arrested in substitution
for springs, which are too uncertain in their action, and are too liable.
to fracture when brought suddenly into action to be safely relied upon
for the purpose referred to.
According to one mode of carrying out this Invention which is
applicable to ordinary miners' cages and hoists for other purposes, a
rack is secured to each of the guide frames, and a pair of safety levers
are carried horizontally on centres in the top cross bar or bars of the
cage or hoist. The outer and short arms of these levers are serrated to
correspond to the racks, and the inner ends of the long arms are con-
nected by links to the hoisting rope or chain, whilst the short arms are
connected by cords or chains passing over guide pulleys to the counter-
weight of the cage, hoist, or lift. So long as the weight of the cage
is on the hoisting rope or chain the safety levers will be held up and
their toothed ends kept clear of the racks, but should the hoisting rope
or chain break then the gravity of the descending cage or lift acting
in opposition to that of the counterweight will cause the short ends of
the safety levers to be lifted and engaged into the rack teeth, thereby
at once arresting the further descent of the cage or lift.
According to a second modification toothed horizontal safety slides
are substituted for the safety levers, such slides being respectively
connected to the lower arms of two double bell crank or T-shaped
levers working on centres in the top cross bar or bars of the cage. The
inner or contiguous ends of the horizontal arms of these T-shapes levers
are connected by links to the hoisting rope or chain, whilst their outer
or opposite ends are connected by other links with the counterweight
rope or chain. The toothed ends of the slides work through metal

page_text: guides attached to the corners of the cage, and are retained clear of
the racks until a breakage of the hoisting rope or chain occurs, where-
upon the action of the cage and counterweight upon the outer ends of
the horizontal arms of the T-shaped levers forces the safety slides out-
wards, and causes their teeth to engage with the teeth of the racks,
thereby arresting the descent of the cage or lift.
According to a third modification applicable where wire rope guides
are used, safety levers arranged and actuated in a manner similar to
those described in the first modification are employed, but in lieu of
being serrated or toothed at their outer ends they are each provided at
that part with a wedge, which wedges, on the breakage of the hoisting
rope or chain, enter the lower expanded mouths of the guide holes in
the cage through which the wire guide ropes pass, and nip the said
guide ropes with sufficient force to arrest the descent of the cap or
lift.
And in order that the said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawings,
the same letters of reference indicating corresponding parts in all the
Figures.
Figures 1 and 2 of the Drawings annexed represent a cage or
hoisting apparatus with one arrangement of the improved safety attach-
ment fitted thereto; Figures 3 and 4 are two views of a modification
of the safety attachment; and Figures 5 and 6 represent another
modification of the same.
On reference to Figures 1 and 2 A represents the cage, and
B, B', the two permanent guiding frames, to each of which is secured
a rack b. To hangers a, a, secured to the top bar or bars of the cage
are hinged two levers D and D', the short arms of which have teeth
adapted to those of the racks b. The ends of the long arms of the levers
are connected by links e, e, to the hoisting chain or rope F, and to the
short arm of the lever D is connected a rope f which passes over suit-
able guiding pulleys, and to which is attached the counterweight H; a
similar rope connected to the lever D¹ passing over guide pulleys,
and being attached to the same weight. In hoisting the cage the long
arms of the levers D and D' are elevated and in contact with the under
side of the cross bar m of the cage, and the teeth of the short arms
of the levers D and D' are clear of the racks b, b, as shewn in Figure 1,

page_text: but should the hoisting chain or rope break the weight H will instantly
raise the short arms of the levers relatively to the cage, so that their
teeth will fit between those of the racks b, b, on the guides B and B',
and will prevent the falling of the cage, as shewn at Figure 2.
In the modification illustrated by Figures 3 and 4 sliding bars D
and D are substituted for the above described levers; these bars are
arranged to slide between two cross bars m, m, of the frame and the
toothed end of each bar passes through and is guided by a plate n on
cach corner of the cage, each bar near each opposite end being guided
by pins or rollers t, t. Two three-armed levers J and J¹ are hung
loosely to pins w, w, on the cross beams m of the cage, the lower arm
of the lever J being connected to the bar D, and that of the lever J¹
to the bar D¹. The arms x, x, of these levers are connected by
links e, e, to the hoisting chain or rope F, and the arms y, y, of the
levers by links 7, 7, to a rope which passes over guide pulleys h and h¹,
and to which is attached the counterweight H. In this modification
when the cage is hoisted the bars D and D¹ are drawn inwards to an
extent limited by their ends coming in contact with each other or with
a suitable stop, as seen on Figure 3. And when the bars are in this
position their teeth are clear of the racks b, b, but should the hoisting
clain or rope F break the arms x, x, of the levers will be set at liberty,
the arms y, y, will be elevated by the counterweight H, and the two
bars D and D' will be simultaneously projected outwards, so that their
tecth will fit into those of the rack, and the cage or hoist will con-
sequently be prevented from falling, as shewn in Figure 4.
In the modification illustrated by Figures 5 and 6 wire ropes M
and M are substituted for the guiding frames and racks shewn in the
previously described Figures, each rope passing through an opening in
an extension m¹ of the cross bars m of the cage or hoist. Each opening
is of such dimensions above as to admit the wire rope freely, but is
enlarged below so as to admit a wedge e¹, one of which is con-
nected loosely to the short arm of each lever. One edge of each is
inclined and adapted to the inclined side p of the opening, the other
edge being rounded to correspond to the concave edge p¹ of such
opening. When the cage or hoist is being raised the long arms of the
levers D and D' are elevated and in contact with the retaining pins t, t,
and the wedges e¹ are depressed, so that the cage is at liberty to slide
freely along the guiding ropes M and M'. Should the hoisting chain

page_text: or rope F break, however, the counterweight H will clevate the short
arms of the levers and their wedges. This elevation of the wedges
combined with the simultaneous effort of the cage to descend will cause
a portion of the guiding ropes to be wedged tightly in the cavities of
the cross beam m, as shewn in Figure 6, and the cage will be promptly
arrested.
Many different devices have been applied to cages with the view of
preventing accidents on the breaking of the hoisting rope.or chain.
Cams, for instance, combined with springs have been used for binding
against guiding frames on the breaking of the hoisting rope. Cams
may certainly be employed with more or less success for bearing against
the smooth sides of frames, but springs are always so unreliable that
when a cage has to depend for its safety on such precarious appliances
it can scarcely be termed a safety cage. Racks and toothed arms, or
their equivalents, are preferable to smooth, or even serrated cams for
binding against the smooth frames as the racks insure the certain
stoppage of the cage before it has acquired the dangerous momentum ;
the racks and toothed arms too arrest the cage without subjecting it and
the frame to the violent strains which arresting cams are liable to
impart.
It will be seen that throughout the several modifications of this
Invention one prominent feature prevails, which is, that the force exerted
by the falling cage to raise the counterweight or rather the force which,
if the counterweight were connected directly to the cage, would be
exerted by the latter to raise the weight is exhausted in arresting the
cage, the force exerted to actuate the arresting arms or rods being
upwards or in a direction contrary to that of the falling cage.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or 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,-
First. Connecting a counterweight of a miner's or other safety cage
or hoist to the mechanism by which the cago is arrested so as to
operate substantially in the manner and for the purpose herein-before
described.

page_text: Second. The use of the arresting levers D and D' applied to a miner's
or other safety cage or hoist, and connected to the hoisting rope or
chain and to a counterweight H, substantially in the manner and for
the purpose herein-before described.
Third. The use of the three-armed levers J and J' connected to the
cage, to the hoisting rope, counterbalance weight, and arresting sliding
bars D and D', substantially as herein-beforè described.
Fourth. The use of the arresting levers D and D¹ connected to the
cage, hoisting rope, and counterweight, as hercin set forth, and having
on each of their short arms a wedge e¹ for jamming the cage to the 1
guide ropes M and M', as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to
this my Specification set my hand and seal, this Tenth day of
December One thousand eight hundred and sixty-eight.
J. HENRY JOHNSON. (L.S.)