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

page_text: Date of Application, 21st Aug., 1897
Complete Specification Left, 23rd May, 1898-Accepted, 2nd July, 1898
PROVISIONAL SPECIFICATION.
Improvements in Hydraulic Breaking Down Apparatus for Mining
Purposes.
I, WILLIAM GEORGE GASS, of the Firm of Entwisle & Gass, Limited, of Atlas
Foundry, Bolton, in the County of Lancaster, Engineer, do hereby declare the
nature of this invention to be as follows:
My said invention relates to hydraulic breaking down apparatus for mining
purposes and refers more particularly to the type of apparatus for which I, in
conjunction with one James Tonge, have obtained Her Majesty's Letters Patent
No. 7441 of 1897.
In the Specification of Letters Patent No. 7441 of 1897 is described inter alia
an expandable bar containing a number of rams adapted to be raised by hydraulic
pressure in order to effect the breaking down of the coal or the like.
I have found in practice that this expandable bar is subject to a disadvantage.
When in use the rams are raised unequally, the work being done either at one
end or the other of the expandable bar. It sometimes occurs therefore, that
before the coal is broken down, one or more of the rams is raised so high that
the cup leather is wholly or partially ejected out of the cylinder. This has the
effect of destroying the pressure by leakage and the efficiency of the apparatus
is consequently impaired.
The object of my invention is to obviate this defect which I do by providing
means to limit the travel of the rams so that in no case can they be raised so
high as to destroy the pressure.
the ram.
In carrying my invention into effect I provide a stop to limit the traverse of
A convenient method of doing this is to reduce the diameter of the
ram throughout the greater portion of its length leaving a collar at the base above
the cup leather. I then screw or otherwise suitable secure, to withstand the
heavy pressure, a ring or collar at the upper portion of the ram chamber through
which the reduced portion of the ram works. When the ram has been raised
a sufficient height the collar bears against the ring or collar at the top of the
ram chamber and thus prevents the further traverse of the ram.
As a modification the stop collar might be formed out of the solid metal and
the ram introduced through an aperture in the base of the bar which aperture
could be closed by a screwed plug or the like.
As my invention consists essentially in providing a stop to limit the travel of
the rams I do not confine myself to the exact methods described as these may be
varied to some extent without departing from the spirit of my invention.
By limiting the travel of the rams and so preventing the escape of pressure as
described the whole of the rams if necessary may be raised to their full working
height and the efficiency of the apparatus is thus increased.

page_text: It may be necessary in conjunction with this arrangement to put a safety or
relief valve or device, at some point of the pump or cartridge to act when all the
rams are at the limit of their traverse.
he Applicant,
E. K. DUTTON & Co.,
Chartered Patent Agents,
5, John Dalton Street, Manchester.
Improvements in Hydraulic Breaking Down Apparatus for Mining
Purposes.
I, WILLIAM GEORGE GASS, of the Firm of Entwisle & Gass, Limited, of Atlas
Foundry, Bolton, in the County of Lancaster, 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:-
My said invention relates to hydraulic breaking down apparatus for mining
purposes and refers more particularly to the type of apparatus for which I, in
conjunction with one James Tonge, have obtained Her Majesty's Letters Patent
No. 7441 of 1897.
In the Specification of Letters Patent No. 7441 of 1897 I described inter alia
an expandable bar containing a number of rams adapted to be raised by hydraulic
pressure in order to effect the breaking down of the coal or the like.
I have found in practice that this expandable bar is subject to a disadvantage.
When in use the rams are raised unequally the work being done either at one
end or the other of the expandable bar. It sometimes occurs therefore that
before the coal is broken down one or more of the rams is raised so high that
the cup leather is wholly or partially ejected out of the cylinder. This has the
effect of destroying the pressure by leakage, and the efficiency of the apparatus
is consequently impaired.
The object of my invention is to obviate this defect which I do by providing
means to limit the travel of the rams so that in no case can they be raised so
high as to destroy the pressure.
And in order that my invention may be fully understood I will now refer to
the accompanying sheet of drawings in which,
Fig. 1 is a cross section of an expandable bar or hydraulic cartridge.
Fig. 2 is a plan of one of the rams.
Fig. 3 is a longitudinal section of a portion of a hydraulic cartridge showing
my invention applied in cases where the rams are arranged to exert pressure
alternately at the top and bottom of the cartridge and,
Fig. 4 shows my invention applied to a telescopic ram.
In carrying my invention into effect I provide a stop to limit the traverse of
the rams.
The most convenient method of doing this is shown in the drawings.
The ram or piston a is reduced in diameter throughout the greater portion of
its length leaving a collar b at the base above the cup leather c. I then securely
screw a washer or ring d so as to withstand the high pressure, at the upper por-
tion of the ram chamber and through which washer the ram a works, as clearly
shown in Fig. 1. The screwed washers are formed with slots as shown in the

page_text: plan view Fig. 2 for the reception of a suitable key or tool by means of which
they are screwed into position or removed when desired.
When the rams a are raised by the water pressure the stop washers & limit
their traverse and prevent the rams from being raised too high.
In Fig. 3 I show my invention applied to a hydraulic cartridge in which the
rams are adapted to work in alternate directions. This arrangement is the same
as that shown in Fig. 1 and need not be further described.
Fig. 4 shows the annlication of my invention to a telescopic ram. The external
ram a is bored out to two diameters as shown in the drawings in dotted lines so
as to present a collar or stop to the internal ram at and limit its outward
traverse, whilst the stop washer d limits the traverse of the external ram a as
already described. The internal ram a is provided with a stud e to prevent
it from dropping down out of the external ram. This stude is screwed and a
nut f thereon secures the cup leather c¹ in position. The cup leather e is secured
by suitable screws or the like to the external ram a.
As a modification the stop washer & might be formed out of the solid metal
and the ram introduced through an aperture in the base of the bar which aperture
could be closed by a screwed plug or the like.
As my invention consists essentially in providing a stop to limit the travel of
the ramis I do not confine myself to the exact methods described as these may be
varied to some extent without departing from the spirit of my invention.
By limiting the travel of the rams and so preventing the escape of pressure as
described the whole of the rams if necessary may be raised to their full working
height and the efficiency of the apparatus is thus increased.
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
I claim is:-
In hydraulic cartridges of the indicated description the provision of stop
washers d or their equivalent to limit the traverse of the rams, the rams being
provided with a collar adapted at the limit of their traverse to abut against the
stop washers, in the manner, for the purposes and substantially as described and
shown.
Dated this 20th day of May 1898.
For the Applicant,
E. K. DUTTON & Co.,
Chartered Patent Agents,
5, John Dalton Street, Manchester.