Improved Valve Actuating Arrangements for Direct Acting Engines, Especially Applicable to Rock Drills.
Year: 1887

page_text: Date of Application, 4th Jan., 1887.
Specification Accepted, 18th Eeb., 1887
Improved Valve Actuating Arrangements for Direct Acting Engines,
Especially Applicable to Rock Drills.
1 PHILIP ARTHUR NEWTON of the Office for Patents 6 Breams Buildings Chancery
Lane in the County of Middlesex, Patent Agent do hereby declaret he 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 :--
This invention relates to that class of direct-acting engines which are more
particularly intended for rock drills and in each of which is employed a main valve
moving as a piston within a valve chest and which is operated or moved alternately in
opposite directions by pressure upon its end.
In this class of engine as most commonly constructed the opposite ends of the main
valve chest are alternately placed in communication with the exhaust so that the
pressure upon the opposite end of the valve will throw or operate it. The main
piston is in some cases provided with annular grooves which serve to establish com-
munication between the main exhaust port and passages leading from the ends of the
valve chest and in other cases the piston has by its movement served to operate
independent supplemental valves at each end of the main valve chest so as to
simultaneously place one end of the main valve chest in communication with the
exhaust and the other end of the valve chest in communication with the steam supply.
Engines of this class as heretofore constructed although they may have been very
effective for a special class of work for which they were designed either as heading
drills or drills for quarry work have not in many cases operated with the best results
when applied to a class of work for which they were not intended.
An important object of the invention is to provide a drill in which the valve is so
constructed and operated that the drill will operate effectively upon any class of work
that is whether employed as a heading drill in funnels or in outside work as in
quarries.

page_text: One feature of the invention consists in the combination with a cylinder and a
piston having reversely arranged inclines or shoulders and a main valve arranged to
move by pressure upon its end, of a supplemental valve which is actuated by the
inclines or projections on the piston to serve the sole purpose of placing the ends of
the main valve chest alternately in communication with the exhaust whereupon the
valve will be moved by the pressure in the opposite end of the chest.
The invention also consists in the combination with a cylinder and a piston having
reversely arranged inclines or shoulders and a main valve arranged to move by
pressure upor its ends, of a single supplementary valve which controls the operation
of the main valve and which is moved in opposite directions alternately by the
inclines or shoulders on the piston. In the above combination it is preferred to make
the supplemental valve in the form of an arc-shaped slide valve which is fitted to a
corresponding seat and which has ports or passages in its flat side or face so that the
valve will always work tight by reason of the pressure of steam or air within the
cylinder keeping it seated." It is also preferred to introduce between the valve chest,
and the cylinder a removable or renewable bed which has a projection fitting within
a cavity or opening within the cylinder and which has formed in such projections the
are-shaped valve seat in which the sliding valve works as hereinafter described.
In the accompanying drawing Fig. I is a longitudinal section upon the plane
indicated by the dotted line, Vig. 2 of such proportions of a rock drill as are
necessary to illustrate the invention. Fig. 2 is a transverse section upon the plane of
the dotted line a Fig. 1. Fig. 3 is a plan view with the valve chest removed and
Fig. 4 is a horizontal section upon the plane of the dotted line yy Fig. 1.
Similar letters of reference designate corresponding parts in the several Figures.
A designates the cylinder in which is fitted the piston B and from the piston B
extends the piston rod B which works through the lower cylinder head and has the
drill or bit secured to it in a well understood manner. designates the main valve
chest in which is the main valve D and E designates a supplemental valve whereby
the movements of the main valve are controlled and whereby in this example of the
invention the ends of the valve chest C are alternately placed in communication with
the main exhaust.
In this example of the invention is illustrated the renewable or removable bed or
plate Fas introduced between the valve chest and the flat surface or face & provided
upon the cylinder and this renewable bed F has a projection F which enters and fits
Joosely in a corresponding cavity or opening formed in the cylinder.
The valve D here represented is of the piston type and serves to alternately place
the main ports or passages in communication with the steam supply and with the
main exhaust port or passage . The main steam and exhaust passages are
curved laterally or carried around the cavity or recess in the cylinder which receives
the block or projection F as shown in Fig. 3 and are continued through the renew-
able or removable bed and the main exhaust port is also continued through the
bed and communicates with the exhaust space or cavity be as shown in Fig. 2 and
from which may lead the exhaust pipe socket .
#
The steam chest or valve chest has in opposite sides pipe sockets with either of
which the steam pipe may communicate and the other of which is closed by a plug 4.
By the movement of the main valve D in one or other direction the port or
passage or will be placed in communication with the main steam supply while
the other port 3 or will be placed in communication with the main exhaust b
As here represented the supplemental valve E is of are-shaped form or in other
words it constitutes a segment of a ring and it is fitted within a slideway or seat d
of corresponding form in the projection F upon the renewable bed or plate F. An
important advantage of this construction is that when the valve E and its seat become
worn so as not to properly fulfill their functions, the valve and its seat may be readily
renewed by removing from the machine the bed or base plate F' with its projection F
and substituting a new one. This may be done at small expense and without removing
the drill from the place where it is worked to the repair shop..
The valve E is slightly greater in length than its arc-shaped seat d and consequently

page_text: one or other end of said valve will project within the bore of the cylinder and in
the path of the inclines or shoulders e el with which the piston B is provided as best
shown in Fig. 1. If the piston be moved toward the left hand of Fig. 1 from the
position there shown its incline or shoulder e will come in contact with the right
hand end of the valve E and will slide said valve toward the left but the distance
between the inclines or shoulders must be such that the inclines or shoulders e will
pass the left hand end of the valve in the described movement of the piston before
the incline or shoulder el comes against the right hand end of the valve to throw it.
toward the left. In the valve E is a recess or cavity which serves to alternately
place the ports or passages in communication with the port or passage. In this
example of the invention where the supplemental valve E serves to place the ends of
the valve chest C alternately in communication with the main exhaust, the port or
passage leads directly to the main exhaust port and cavity and the passages/"
are in constant communication with the steam passages which are formed in the
valve chest C and which lead to opposite ends thereof. It is preferred to form the
recess or cove e of the valve E in the side or flat face of said valve as the pressure
which is within the cylinder will then serve to keep the valve E pressed tightly to its
seat and will prevent leakage.
In the position of parts shown in Fig. 1 the supplemental valve E is in such
position that by its cove or cavity the passage is in communication with the
passage and consequently the right hand end of the valve chest. C is in free
communication through said passages with the main exhaust. The supplemental
valve E has been previously set in the position described by the movement of the
piston B toward the right hand of Fig. 1 and by the action of the incline or shoulder e
upon the left hand end of the valve E. As soon as the right hand end of the valve
chest. C was placed in communication through the passages", with the main
exhaust the pressure which had accumulated in the left hand end of the chest C by
the slight leakage past the valve D served to throw the valve toward the right and to
the position shown. The piston B as shown is at the extreme right hand end of its
movement and in the position of the valve D shown the passage is in free
communication with the inain exhaust port or passage while the passage 6 is open
to steam supply in order to admit steam to the right hand end of the cylinder A.
the piston by the pressure of steam upon its right hand end comes near the end of its
working stroke the incline or shoulder acts upon the right hand end of the valve E
and by moving it places the passages in communication through the cavity or
cove e of the valve. By such movement of the valve the left hand end of the valve
chest C is placed in free communication with the main exhaust and the left hand end
of the valve D being relieved of pressure said valve is moved toward the left hand of
Fig. 1 by the pressure upon its opposite end and thereby places the passage 63 in
communication with the exhaust and admits the live motive agent through the
passage to make the return movement of the piston.
As
It will be observed that the supplemental valve which is above described is very
simple in its construction and will work tight notwithstanding the wear to which it.
may be subjected. It may also be renewed at small cost when by long continued
wear such renewal is made desirable.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed as communicated to me by my
foreign correspondent I declare that what I claim is :—
1. The combination with a cylinder, a piston having reversely arranged inclines or
shoulders and a main valve arranged to move by pressure upon its end, of a supple-
mental valve which is actuated by the inclines or projections of the piston to serve the
sole purpose of placing the ends of the main valve chest alternately in communication
with the exhaust whereupon the valve will be moved by the pressure in the opposite
end of the chest substantially as herein described.
2. The combination with a cylinder, a piston having reversely arranged inclines or
shoulders, and a main valve arranged to move by pressure upon its end, of a supple-

page_text: mental valve which controls the operation of the main valve and which is moved in
opposite directions alternately by the inclines or shoulders on the piston substantially
as herein described.
3. The combination with the main cylinder, a piston having reversely arranged
inclines or shoulders and a main valve arranged to move by pressure upon its end, of
a supplemental are-shaped slide valve fitted to a corresponding seat and arranged to
be moved in opposite directions alternately by the inclines or shoulders of the piston,
to control the operation of the main valve substantially as herein described.
4. The combination with the main cylinder, a piston having reversely arranged
inclines or shoulders and a main valve arranged to move by pressure upon its end, of
a supplemental are-shaped valve fitted to a corresponding seat arranged to be moved!
in opposite directions alternately by the inclines or shoulders of the piston, and
having a port or cavity in its flat side or face for controlling the operation of the main
valve substantially as herein described.
5. The combination with the cylinder A. having a cavity or opening the piston B
having inclines or shoulders eel, and the main valve cliest and its valve D, of the
renewable bed F for the valve chest provided with the projection F₁ having formed
therein the arc-shaped valve seat d and poris fff", and the are-shaped supplemental
valve E fitting said seat and arranged to be moved by the inclines or shoulders on
the piston substantially as herein described.
NEWTON & SON,
Agents for the Applicant.