Improvements in Hydraulic Breaking Down Apparatus for Mining.
Year: 1897

page_text: Date of Application, 23rd Mar., 1897-Accepted; 8th May, 1897
COMPLETE SPECIFICATION.
Improvements in Hydraulic Breaking Down Apparatus for Mining.
Purposes.
We WILLIAM GEORGE GASS, of the Firm of Entwisle & Gass Ltd., of Atlas
Foundry, Bolton, in the County of Lancaster, Engineer, and JAMES TONGE, of
Albany Chambers, Bolton, aforesaid, Mining Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement and
accompanying drawings :-
We
Our said invention relates to improvements in hydraulic apparatus for breaking
down coal and minerals in mines as is well understood. Such breaking down in
mines is usually effected by shot firing but to this method numerous objections apply.
e are aware that hydraulic apparatus for the same purpose has been proposed,
but owing to defects in construction such apparatus has never been practically
successful. The object of our present invention is to remedy such defects and to
produce a breaking down apparatus which will work successfully, while in combi-
nation therewith we have devised improvements in the forcing pump and in the
method of connecting the same to the apparatus the effects of which are to facilitate
its application and render its operation more certain.
In order that our said invention may be more clearly understood we will now
proceed to describe the same with reference to the annexed sheet of illustrative
drawings.
Fig. 1 is a longitudinal side view of a chambered bar containing a series of
hydraulic rams.
Fig. 2 is a longitudinal section.
Fig. 3 is a cross section of the bar.
Fig. 4 is a cross sectional view of a protecting metallic clip to box in the rams
and protect them from dirt.
Fig. 5 is an end elevation of the force pump for creating the hydraulic
pressure.
Fig. 6 is a side view of the pump partly in section.
Fig. 7 is a general view of the bar and pump in working position.
The improved apparatus consists of an expandable body or bar a intended
to be inserted in a hole in the coal or mineral drilled to receive it and above the
mass which it is desired to break down as shown in Fig. 7.
+
This expandable body or bar a consists of two chief parts, viz., the main portion
or ram box a containing a number of hydraulic rams 6 and one two, three or more
separate covers ccc which rest upon the rams or rather upon the metallic clip d
which covers in the rams.
The rams bare merely cylinders of metal packed at the foot with cup leathers 61
and working in a series of separate holes in the ram box a. Small ports a formed
through the solid metal separating each of the said ram holes establish communi-
cation between the ram holes.
The water pressure is forced in at the front of the ram box a through the pipe e
and along the port a¹ to the first ram chamber the pressure thus finding its way
beneath the whole of the rams b. The top of the rams where they bear against
the inner side of the clip and superimposed covers c c c are dome shaped and
provide for any lateral rocking or relative movement or displacement of the covers
1 Pins81

page_text: and the ram box, the covers merely rolling upon the dome shaped crowns of the
rams without straining or disturbing the rams in their holes. This prevents
jambing and possible breakage and leakage of the apparatus. To prevent the
covers from slipping longitudinally upon the ram box we turn them down at
the ends so that they clip over each other loosely and over the ends of the ram
box thus mutually preventing relative movement. Also to prevent dust or dirt
from having access to the rams, we place over the top of the ram box or attach to
the inner cover c of the series a metallic protector clip d of thin sheet steel or other
suitable metal and projecting sufficiently far on each side to embrace and partly
surround the ram box as seen in Fig. 3 for example.
Thus when not in working position the apparatus can be handled as if it were a
hemogeneous body.
To prevent the rams from being raised too high in the ram box we provide relief
holes at the point beyond which it would be unsafe to raise the rams.
The covers c c c are made multiple because if one strong cover is used it
apt
to be bent and cannot easily be straightened on the spot, whereas the several covers c
when combined are of sufficient strength with the added advantage that if bent they
can singly be more easily straightened.
Moreover if one cover only were used if the hole drilled for the reception of the
apparatus is of much larger diameter than the apparatus, the cover is raised to some
extent before bearing against the coal or other mineral being operated upon ani a
serious loss in efficient working ensues.
Whereas by the employment of multiple covers it would only be necessary to
apply additional covers until the apparatus was brought to bear directly upon
the coal.
The full power of the apparatus could thus be exerted.
The front end of the ram box a is connected by tubing e e¹ (see Fig. 7) to the
portable force pump g. The pump is supported on a tubular bar having a cross
piece h¹ at the foot.
The pump
is adjustably attached to the said bar h by an eye
bolt the eye of which embraces the bar h while the screwed tail passes loosely
through the body of the pump, the bolt being tightened or slackened by a screwed
handle or wrench j.
To assist the gripping action of the bolt eye on the bar we re-enforce it by the
addition of a trough or other suitably shaped slip binder bracket & shown in Fig. 5
and also in side view in the separate detail view Fig. 5A.
One side of the bracket rests against the body of the pump and thus supports
and prevents the tube from being bent by the eye bolt, while the pressure of the
bracket increases the bite on the tube. The pump can by the indicated means be
adjusted to any desired height. The pump is also partially supported by the
connecting tubing eel, these two tubes being united by the coupling . The pump
may be lifted and carried about from place to place by the handle 1. The pump
plunger o is worked up and down by the handle m pivotted at m to the side
cheeks n, the upper end of the plunger being steadied by a guide p. The
handle in has a loose extension m² which can be applied when increased leverage is
required. Thus pressure may be quickly pumped up with the short handle in the
extension m³ being mounted to increase the leverage when the maximum pressure
is being developed. The water is drawn from a bucket or other receptacle (such
as g in Fig. 7) by means of a flexible pipe r and passes first through a check valve s
to the chamber beneath the plunger.
The flexible piper is provided at its free end with a gauze strainer or rose to
prevent the admission of dirt to the pump chamber.
From the pump chamber the water is forced by the downward stroke of the
plunger through the valves t and u and through the tubings ee to the rams b.
We prefer to use the double valves t and u for the reason that they increase the
security against loss of pressure by back leakage, since if one valve fails the other
will hold good. In practice we have found that to enable the force pump to be
conveniently operated manually in the mines a plunger of small diameter of say,

page_text: inch only could be used. Where a plunger of larger diameter was used the
extra power required to be exerted could not be conveniently applied in the cramped
space within which the apparatus is required to be used. The amount of water
pumped at each stroke with a plunger of this area is very small and owing to
leakage of the valve it was found impossible to get up the pressure to more than
about 15 cwts. per square inch which was totally inadequate to effect the purpose..
By the employment of a second valve the leakage was obviated and actual working
pressures of from 1 to 2 tons per square inch were obtained. A screw down
valve v on the tube el is used to release the pressure beneath the rams b. A pressure.
gauge w may be fixed above the valve as shown to indicate the pressure.
The whole apparatus is combined and used as shown in Fig. 7. The fig.
shows a section of coal undercut and spragged at the foot as usual and having
a hole drilled to receive the expandable bar a as indicated.
When the pressure is pumped beneath the rams the expansion of the bar a due
to their movement breaks down the mass of coal marked x as indicated by the
dotted line y. The expandable bars may be used singly or when desired, in a
series.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is.
1. In hydraulic apparatus for breaking down coal and minerals in mines, the
combination with an expandable bar such as a of a series of rams made with.
rounded or dome shaped tops and employed in conjunction with a series of separate
and loose covers c and clip protector d for the purposes and substantially as
described and shown.
2. In hydraulic apparatus for breaking down coal and minerals in mines, the
combination of an expandable bar of the kind as set forth in the foregoing claim,
with a force pump adjustably supported on a standard such as h and constructed
with duplicate back pressure valves, substantially as described and shown.
3. The general arrangement, construction and combination of complete hydraulic
apparatus for mining purposes, substantially as described and shown.
Dated this 19th day of March 1897.