IMPROVEMENTS IN MACHINERY FOR EXCAVATING COAL, STONE, AND OTHER MINERALS, AND FOR COMPRESSING AIR
Year: 1870

page_text: LETTERS PATENT to Samuel Firth, of Leeds, in the County of York,
and Frederick Hurd, of Rochdale, in the County of Lancaster,
Engineer, for the Invention of "IMPROVEMENTS IN MACHINERY FOR
EXCAVATING COAL, STONE, AND OTHER MINERALS, AND FOR COMPRESSING
AIR."
1
Sealed the 5th August 1870, and dated the 26th February 1870.
PROVISIONAL SPECIFICATION left by the said Samuel Firth and
Frederick Hurd at the Office of the Commissioners of Patents,
with their Petition, on the 26th February 1870.
We, SAMUEL FIRTH, of Leeds, in the County of York, and FREDERICK
HURD, of Rochdale, in the County of Lancaster, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN MACHINERY
FOR EXCAVATING COAL, STONE, AND OTHER MINERALS, AND FOR COMPRESSING
AIB," to be as follows:-
4.
The improvements in machinery for excavating coal, stone, and other
minerals, consist in connecting a series of cutters to an endless wire

page_text: rope instead of fixing the same to the links of a chain as described in a
Patent granted to the above-named Frederick Hurd, on the 25th day
of March 1869, No. 906. Also in driving the said endless wire rope
by a friction pulley with wedge-shaped segments fitting. between dises
and on a central circular wedge. Also in supporting the endless wire
rope or chain of cutters on flanged pulleys mounted on the radial arm.
Also in making the cutter stocks in two pieces secured to and enclosing
the wire rope. When the wire rope is driven by the friction clip pulley
the rope is flattened where the cutter stocks are fixed to it; but when
the wire rope is not flattened it can be driven by a toothed_or_notched
disc on the fulcrum of the radial-arm. Also in the machinery for hauling
or traversing the cutting machinery along the face of the mineral,
consisting of a pair of friction rollers placed diagonally to the rail
instead of being at right angles thereto as described in the Patent
granted to the within-named Samuel Firth in conjunction with William
Firth on the 31st day of May 1864, No. 1352. The object of placing
the rollers diagonally is to facilitate the passing over the joints of the
rails. The rollers are connected to a spring lever which is acted
upon by a screw or other equivalent, the spring lever compensating
for the unequal thickness of the rails. When it is requisite to clear
the rollers from the rail the lever is moved so as to bring the rollers at
right angles to the rail, and they can then be raised by a screw or
otherwise. Also in boring annular recesses, in coal and other minerals
by an archimedian shell screw cutter, consisting of a barrel with one
or more threads terminating in a cutter or cutters. This shell is
turned by hand or power and pressed into the mineral to be cut,
also in driving excavating machinery by rotary, steam, or other engines.
Our improvements in machinery for compressing air consist in applying
the power to the longer arm of a differential lever, and in connecting
the shorter arm to the machinery for compressing air, also in applying
the pressure of air as a govenor. As the pressure of steam in the
engines usually employed at collieries is not of sufficient force for
compressing the air to work the excavating machine direct, we apply
the differential lever in the manner above described to increase the
pressure on the air which is conveyed to a receiver or direct to the
excavating machine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Samuel Firth and Frederick Hurd in the Great
Seal Patent Office on the 25th August 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, SAMUEL
FIRTH, of Leeds, in the County of York, and FREDERICK HURD, of
Rochdale, in the County of Lancaster, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of February, in the
year of our Lord One thousand eight hundred and seventy, in the
thirty-third year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Samuel Firth and Frederick
Hurd, Her special licence that we, the said Samuel Firth and Frederick
Hurd, our executors, administrators, and assigns, or such others as we,
the said Samuel Firth and Frederick Hurd, our executors, adminis-
trators, and 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 MACHINERY
FOR EXCAVATING COAL, STONE, AND OTHER MINERALS, AND FOR COMPRESSING. AIR,"
upon the condition (amongst others) that we, the said Samuel Firth
and Frederick Hurd, our executors. or administrators, by an instrument
in writing under our, or their, or one of our or their hands and seals,
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 Scal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent..
NOW KNOW YE, that we, the said Samuel Firth and Frederick
Hurd, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following. Specification thereof, reference
being had to the three accompanying Sheets of Drawings, and to the
figures and letters marked thereon:—
The various Figures on Sheet 1 represent some of our improvements
in machinery for excavating coal stone and other minerials - which

page_text: First. In connecting a series of cutters to an endless wire rope, instead
of fixing the same. to the links of a chain as described in a Patent
granted to the above-named Frederick Hurd on the Twenty-fifth day
of March One thousand eight hundred and sixty-nine, Number 906.
And secondly. In driving the said endless wire rope or other rope,
chain, or band, by a friction clip pulley with wedge-shaped segments
fitting between discs and on a central circular wedge.
Fig. 1 is an elevation partly in section, and Fig. 2 a plan of our
improved friction clip pulley, consisting of the two discs a,a,-which-
are keyed on the axle b. Between-these discs are the wedge-shaped
_segments or grips c, c, one of which is shewn detached in Fig. 3. Each
segment has a midfeather fitting in a recess in the disc, and the inner
ends of the segments have projections fitting in grooves in the central
circular wedge d, which is also keyed to the axle U. The wire rope e,
which is shewn in section in Fig. 1, fits between the wedge-shaped
segments c, c, and as the tension on the rope increases the segments
are pressed towards the centre of the pulley, thereby causing the inner
ends of the segments to be expanded by the circular wedge d, and the
outer parts to be contracted by the discs a, a. By this means the clip
of the segments is increased in proportion to the tension on the rope.
When the tension on the rope is relieved at the off side of the pulley the
segments ċ being at liberty to expand release the rope, as shewn at the
lower side of Fig. 1. The segments are prevented from falling out of
the discs by the projections c¹.
Fig. 4 is a plan, and Fig. 5 a section of part of a wire rope, shewing
the mode of connecting the cutters thereto; e is the wire rope, and the
stocks, in which the cutter g is fixed. The stocks are in two parts
rivetted together and the recesses in the stocks are curved, as shewn
in Fig. 6, so that the wire rope may be compressed and securely held
between them.
Fig. 7 represents a plan of part of a coal getting machine shewing
the mode of applying our improved friction clip pulley and the mode of
supporting the endless wire rope with cutters on flanged pulleys
mounted on a radial arm; a is the friction clip pulley around which
passes the endless wire rope e. The radial arm is jointed to the axle b
of the pulley a, and in the radial arm arc mounted four or other con-
venient number of flanged pulleys. which support the endless wire
rope. The pulleys may also be applied to support an endless chain of

page_text: cutters, constructed in the manner described in the Patent of Frederick
Hurd above referred to. The object of these pulleys is to reduce the
friction on the wire rope or on the chain of cutters..
Figs. 8 and 9 represent the mode of connecting the cutter stocks to
the endless wire rope when it passes around a friction clip pulley. In
this case the wire rope must be flattened where the cutter stocks are
fixed to it, and the lower edge of the stocks must be in a line with the
under side of the rope; but when the stocks project beyond the rope, as
shewn in Fig. 4, it may be driven by a toothed or notched disc on the
fulcrum of the radial arm.
Our improvements in the machinery for hauling or traversing the
cutting machinery along the face of the mineral, consists of a pair of
friction rollers forming a revolving clip placed diagonally to the rail,
instead of being at right angles thereto, as described in the Patent
granted to the within-named Samuel Firth, in conjunction with
William Firth, on the Thirty-first day of May. One thousand cight
hundred and sixty-four, Number 1352.
}
is
This part of our Invention is shewn in Figs. 10 and 11 of Sheet 2.
In these views j is one of the rails on which the coal cutting machine
runs, and is part of the coal cutting machine, to which the movable
bracket ¹ is fixed. In this bracket is the stud l forming the fulcrum of
the lever, which is provided with bosses to receive the. upright shafts m.
To the lower end of these shafts are fixed the rollers n which clip on
the head of the rail j, and to the upper ends of the said shafts are fixed
the spur wheels n¹. To one of the shafts m is fixed a hand wheel ², to
move the machine by hand if desirable, as described in the Patent
granted to William and Samuel Firth above referred to. The lever
provided with a swivel block P, through which the screwed shaft o
passes. The swivel nut of this screwed shaft is connected to the frame
of the cutting machine, and a strong spring o¹ is placed between the
end of the swivel block and the boss of the hand wheel o². The object
of placing the rollers n diagonally is to facillitate the passing over the
joints of the rails, and the spring o¹ acting upon the lever is to com-
pensate for the unequal thickness of the rails. When it is requisite to
clear the rollers n from the rail the lever is moved by turning the
screw o, so as to bring the lever and rollers n at right angles to the
rail, and they can then be raised by a screw or lever acting on the

page_text: bracket. The rollers 2 forming a revolving clip may be applied to a
rope instead of the rail j, as shewn,
Fig. 12 is a side view, and Fig. 13 a section of an archimedian shell
screw cutter, consisting of the barrel p made of cast or wrought iron
with one or more threads p¹ cast or forged upon it. Each thread, when
more than one is used, terminates in a cutter p², which is keyed to
the thread. This shell is turned by hand or power and pressed by a
screw or otherwise into the mineral to be cut. When the cutter has
penetrated to a sufficient depth into the mineral it is drawn back and
brings with it a cylindrical block of the mineral. In getting coal the
cutter is applied-to-the-lower part of the scam, and after a sufficient
number of adjacent holes have been bored the coal can be wedged down
as usual, or the cylindrical blocks so obtained may be used to facilitate
transit. As the pressure of steam in the engines usually employed.
at collicrics is not of sufficient force for compressing the air to work
the excavating machine direct, we employ a differential lever to increase
the pressure on the air which is conveyed to a receiver or direct to the
excavating machine.
Fig. 14 represents a convenient arrangemeut for carrying this part
of our Invention into operation. q is supposed to be the ordinary
colliery steam engine the piston rod of which is connected to the cross
head and slide q¹. This cross head is connected by the link to the
longer arm of the differential lever 21, the shorter arms of which give
motion to the force pumps or other machinery for compressing air.
By varying the relative proportion in the lengths of the longer and
shorter arms of the differential lever it is evident that the air can be com-
pressed to any extent by a steam engine of comparatively small power.
On Sheet 3, Fig. 15 is a plan, and Fig. 16, a side view, both partly in
section of another mode of applying the differential lever above referred
to, and our improvements in applying the pressure of air as a governor;
Fig. 17 is a detached view of part of the same, and Fig. 18 an enlarged
view of the governor; q, q, are two oscillating cylinders actuated by
steam, air, or water, similar to those described in the Patent granted.
to Frederick Hurd above referred to, the piston rods of which are united
at the crank pin q' which is connected by the link to the longer arm of
the differential lever 7, the shorter arm of which is in communication
with the force pump s, the compressed air from which is discharged
through the orifices &¹ into the pipe which is in communication with.
T

page_text: the receiver t, shewn partly in Fig. 17. The air from the. receiver
passes through the pipe t' to the self-registering pressure and weight
guage, consisting of the stationary plate with segmental openings to and
the movable plate with corresponding openings ³, as described in the
Patent of Frederick Hurd, above referred to. To the spindle of the
plate is fixed the weighted elbow lever t, the vertical arm of which
is connected to the piston u, fitting in the cylinder u¹. The air from the
receiver passes through the elbow pipe u² to the face of the piston
and regulates the position of the plate , according to the working
pressure determined upon. The air after passing through the self-
registering pressure and weight guage is conveyed through the pipe v
to the excavating machine, and the branch pipe v₁ is in communication
with the engines by which the air is compressed. By this arrangement
the compressed air in excess of that required for working the excavating
machine is conveyed back to the motive power engine. A second self-
registering pressure and weight guage is applied in the pipe v¹ to give
and shut off the excess of air to the motive power engine.
Our Invention consists also in driving excavating machinery by.
rotary, steam, or air engines of any description.
Having thus stated the nature of our Invention and described the
manner of performing the same, we declare that what we claim is,―
First. Connecting a series of cutters or cutter stocks to an endless
wire rope.
Secondly. The improved friction clip pulley with sliding wedge-shaped
segments or grips for holding and releasing ropes, chains, or bands,
endless or otherwise, as shewn and described.
Thirdly. The application of flanged pulleys to the radial arm for
supporting the endless wire rope and cutters or an endless chain of
cutters, as shewn and described.
Fourthly. Propelling excavating machines or engines by revolving
clips placed diagonally to the rail or rope, as shewn and described.
Fifthly. The archimedean shell screw cutter substantially as shewn
and described.
Sixthly. The application of a differential lever to machinery for
compressing air, as shewn and described.
Seventhly. The self-registering pressure and weight guage, shewn and
described.

page_text: Eighthly. The application and use of compressed air as a self-acting
governor, as shewn and described.
And, ninthly. The application of rotary, steam, or air engines for
driving excavating machinery.
In witness whereof, I, the said Frederick Hurd, for myself, and 5
on behalf of the said Samuel Firth, have hereto set my hand
and scal, this Twenty-fourth day of August One thousand eight
hundred and seventy..