IMPROVEMENTS IN MINING WEDGES OR TOOLS FOR BREAKING UP COAL OR OTHER MINERAL
Year: 1885

page_text: I CUTHBERT BURNETT of Burn Terrace Hartlepool in the County of Durham
Engineer do hereby declare the nature of said invention for IMPROVEMENTS IN
MINING WEDGES OR TOOLS FOR BREAKING UP COAL OR OTHER MINERAL to be as
follows:-
In the specification of my patent dated 12th Jan 1884 N° 1351 I have described
and claimed in mining wedges or tools the combination with a wedge shaped bar
and parallel bars or feathers or with wedge shaped side bars and parallel jambing
bars or taper side bars and taper wedging bar of antifriction rollers or balls so
arranged and operating by the rollers ascending on the inclined surfaces as to
produce expansion of the bore hole and bursting the walls of same.
Now according to my present invention while following the main features of
the said previous invention I improve the construction and action of such tools in
the following manner, I form or provide at or in continuation of the end of the
screw a wedge which is thinner at its screw end and thicker at its other end.
This screw and wedge bar is enclosed between two bars which are placed in the
bore hole and with a shoulder rest against the face of the coal. These bars are
from near the end formed with a long easy taper inside and rollers or balls are
placed in the intervals between the inner taper bar and the two outer taper bars,
which latter have shoulders for keeping the rollers in.
A nut placed on the screw and abutting against the ends of the two outer bars
gives facility for pulling the inner taper bar out towards the face of the coal
whereby the rollers while ascending on the inclines of the inner taper bar and the
inclines of the outer taper bars will force the latter apart thus bursting the bore
hole. To turn the nut I by preference employ the following appliance. On the
This is worked in the first instance
nut I provide a square for a handle to fit on,
but when the work becomes too hard I use a supplementary purchace and handle.
The nut is provided with a pawl wheel the pawl for which is fitted in a fork
swivelling on the nut like a ratchet brace and provided with a slot for a bush or

page_text: cam roller to work in which is fitted with a square for the supplementary handle.
This bush is mounted freely on a pin fixed to an arm or bracket fixed to the end
of the two aforesaid lateral bars and has a segmental edge incision in which fits a
smaller roller also mounted freely on a pin which is fixed on the fork.
As the supplementary lever is worked the first named bush or roller will with
the edge of its segmental excision mount on the other or smaller roller and thus
move the latter with the fork in which it is mounted and therewith also the
pawl connected thereto, thus turning the pawl wheel. In the return stroke of the
supplementary lever the larger roller will resume its first position in the slot in
the fork.

page_text: Coal or other Mineral.
I, CUTHBERT BURNETT of Burn Terrace, Hartlepool in the County of Durham
Engineer do hereby declare the nature of this invention and in what manner the
same to be performed, to be particularly described and ascertained in and by
the following statement :-
In the Specification of my Patent dated 12th January 1884 No 1351 I have
described and claimed in mining wedges or tools, various forms of the combination,
with a wedge-shaped bar and parallel bars or feathers, or with wedge-shaped side
bars and parallel jambing bar, or with taper side bars and taper wedging bar, of
antifriction rollers or balls so arranged and operating by the rollers ascending on the
inclined surfaces as to produce expansion of the borehole and bursting the walls
of same..
Now according to my present invention while following the main features of the
said previous Invention I improve the construction and action of such tools in the
following manner.
In the accompanying drawings I have shewn at Figure 1 in vertical longitudinal
section a mining wedging tool with the key or handle for actuating the ratchet of
the threaded nut all constructed according to my invention and at Figure 2 a cross
section on line x y of Figure 1 and Figure 3 a cross section on line x1 y1 of the
same Figure. Figure 4 is a vertical transverse section shewing position of bore
hole in mass of coal into which the instrument is introduced: this figure is drawn
to a reduced scale to the previous Figures.
Figure 5 shews in vertical longitudinal section on a larger scale than Figure 1
the outer or front end of the wedging apparatus showing the compound ratchet
brace. Figures 6 and 7 are an end view and vertical cross section respectively of
the same. Figure 8 is a sectional side elevation of a modified arrangement of the
outer or front end of the wedging apparatus, and Figure 9 a plan of same Figures 10
and 11 are respectively part sectional side view and plan of the ratchet lever or
handle detached.
The same letters refer to like parts in all the Figures.
Referring specially to Figures 1 to 7, A is the wedge, formed or provided at or
in continuation of the end of the screw and made thinner at its screw end and
thicker at its other end where it is formed with an enlargement or head A*.
This screw and wedge bar conveniently made with a plain or parallel "part A'
between the wedge A and the screw A² is enclosed between two bars or feathers B
and B which are placed in the borehole. For this purpose instead of making
these two bars B B* plain on their inner faces as according to my aforesaid patent
I make them of a channel section as shown in Figure 2, that is to say with a
ledge or rib on each side which enclose the wedge bar and thus while affording
greatly increased strength serve also to keep the rollers C in place sideways, thus
enabling me to dispense with the frame e¹ of my former patent in which the rollers
were mounted. Instead of the feathers being rivetted into the flange or shoulder D
resting against the face of the coal, I prefer either to dovetail the feathers into the
shoulder or flange D or provide them as here shown with T heads fitting into
corresponding recesses in the flange D These bars are from near the end formed

page_text: with a long easy taper inside and the bottom bar B* which has to bear the greater
weight or strain is made stronger than the top bar B as shown and the rollers C or
balls are placed in the intervals between the inner taper bar A and the two outer
taper bars B and B*. There are shoulders at b b and at A* and A° for keeping
the rollers in. A nut E placed on the screw and abutting against the ends of the
two outer bars gives facility for pulling the inner wedge bar A out towards the
face of the coal whereby the rollers C while ascending on the inclines of the inner
taper bar A and the inclines of the outer taper bars B and B will force the two
latter apart thus bursting the bore hole. The nut E is formed with a flange which
is held in place against the flange D by means of a bearing plate Ex and two (or
more) bolts D³, the shoulder D and bearing plates Ex having lugs therefor as shown.
To turn the nut EI employ the following appliance. On the nut I provide a
square E for a ratchet handle or lever to fit on. The ratchet lever may suitably
be about two feet in length and preferably constructed as shown in Figures 10
and 11 which can conveniently be operated in a limited space. In this manner the
wedge is worked in the first instance as far as possible but when the work becomes
too hard to be conveniently done I use a supplementary purchase and lever. For
this purpose I take the ratchet lever off the square E, and first lock the "nut" or
ratchet wheel K Figures 8 and 9 by means of the pawl K' and now use the ratchet
lever as an ordinary lever and apply it to the square H' of the lever H or I may
use an ordinary lever fitting the square H as a supplementary lever. The nut E
is provided with a pawl wheel E the pawl F for which is fitted in a fork G
swivelling on the plain parts of the nut E like a ratchet brace and the fork G-is
provided with a cam like slot for a bush or boss forming a lever H to work in,
which boss is fitted with the square H' for the ratchet lever K (or supplementary
lever). This boss or lever H is mounted freely on a pin D' fixed to an arm or
bracket D extending from the flange D which is secured to the ends of the
two aforesaid lateral bars B B and has a segmental edge incision which fits the
circumference of a smaller roller H³ also mounted freely on a pin which is fixed in
the fork end H'H' of the lever H. This roller H³ works in the cam slot Œ¹ in
the fork G. As the ratchet or supplementary lever is worked the boss of the
lever H will with the edge of its segmental excision mount on the other or smaller
roller H³ and thus move the latter in and with the fork G in which it is placed
and therewith also the pawl F connected thereto, thus turning the pawl wheel E¹.
In the return stroke of the lever on the square H' the boss H will resume its first
position in the slot in the fork G. By this construction of parts I obtain an
increased power in direct proportion to the ratio of leverage between the lever H
and lever G the ratio of leverage being nearly uniform while the whole is self
contained.
By the improved form of the feathers B B* and thus also doing away with the
frame or carriage in which the rollers were mounted (according to my previous
patent) the apparatus is much reduced in size, so that the hole into which it is
inserted is drilled much smaller; the friction is also much reduced, while the
general efficiency and convenience of the apparatus is enhanced. The wedge bar
it will be seen travels double the distance of the rollers, I thus obtain twice the
power of any other wedge of the same taper and length of taper and pitch of
screw. The wedge might be made double but such increase of power I do not
at present want. It will also be understood by comparison with the specification
of my aforesaid previous patent that the improvements herein before described
are also applicable to a wedge shaped jambing bar with parallel feathers, or to a
parallel jambing, bar with taper feathers. Referring again to the ratchet lever
shown in Figures 10 and 11, K is the handle of same the head of which is formed
with a fork carrying between its two prongs K¹ K' the ratchet wheel K the pro-
jecting cylindrical bosses K³ of which revolve in bearings formed by the said
prongs K¹ K. Pivotted to the base of the fork on one side is a pawl K' for
rotating the ratchet wheel K2 and kept to its work by a spring and on the other
is pivotted a hooked catch K by which the ratchet wheel K may be locked with

page_text: the handle when desired as already explained. By this construction of ratchet lever
I may when applied to the square end of the crank H obtain such an advantageous
relative position for the handle K as may be found most convenient for the effec-
tive operation of same without shifting the handle from either of the square ends
whichever it might at the time be applied to also by locking the ratchet wheel
with the handle by means of catch pawl H5 (it being observed that the base of the
teeth of the ratchet are somewhat square cut) I am enabled to use this handle
as an ordinary plain handle and for operating on either of the square ends left
or right.
The modified wedge apparatus shewn in Figures 8 and 9 differs from that shown
in Figures 1, 2, 3, 5, 6 and 7 in that conical rollers L are interposed between the
flange or shoulder D and the flange end of the nut E for the purpose of materially
diminishing the friction at this place. Figure 9 also shows more clearly the holes
for the T heads of the feathers or bars B B*.
The application and action of my improved mining wedge tool in say for instance
the ordinary coal mining operations is as follows:-The coal having been cut away
at its lower part and the wedge hole or holes drilled as shown by Figure 4 the
wedging appliance is inserted into such a hole as shewn at Figure 1: the ratchet
handle or key K is then affixed on to the square E' formed on the extended portion
of the nut E which latter is thereby rotated and the said nut E bearing against
the shoulder D will begin to withdraw the wedge A. The operator will continue
this I may say direct action of the handle K on the square end E2 of the nut E
until more power is required than can thus be directly obtained. He then shifts
the handle or key onto the square H* of the forked crank H and by imparting
successive to and fro partial rotations to same the roller H³ acting against the cam
slot G¹ of the fork G will cause the pawl Fon the fork G to pass say a tooth at
each oscillation caused by the motion given to the crank H and thus very great
power will be obtained and thereby causing the final bursting of the bore hole
with of course a proportionate loss of speed in the motion.
The wedge bar A is prevented from being withdrawn too far and 80 allowing
the rollers to pass its larger end by said end A* being 'swelled or enlarged and
the ends b of the outer bars B B being also enlarged or bent inwards as already
stated this latter formation of the bars B B* further preventing the rollers escaping
as already explained when the bar A is in the position shewn at Figure 1.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed I declare that what
I claim is.
First. The combination with wedge shaped inner jambing bar and channelled
parallel outer bars or feathers, or with parallel inner jambing bar and channelled
taper outer bars or feathers, or with wedge shaped inner jambing bar and
channelled taper outer bars or feathers, of antifriction rollers arranged on each
side of the jambing bar substantially as described whereby the jambing bar
travels twice the distance of the rollers and double power is obtained.
Second. The improved construction of mining wedge substantially as described
and shewn.
Third. The improved construction of duplex gear for working mining wedges
substantially as described and shewn.