Improvements in Rock Boring Machinery.
Year: 1889

page_text: Date of Application, 27th June, 1889
Complete Specification Left, 26th Mar., 1890-Accepted, 26th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in Rock Boring Machinery.
WILLIAM MCNEILL of 29 North Villas Camden Square N.W. in the County of
Middlesex Mining and Mechanical Engineer do hereby declare the nature of this
invention to be as follows
For the purpose of obtaining reciprocating motion of the piston rod and boring
tool in rock boring machinery, I place between two pistons on a piston rod within
the main cylinder a sleeve or cylinder in one piece. On this sleeve which I term the
valve sleeve I make two slots the direction of these slots is not coincident with the
axial line of the pistons & piston rod but departs right or left of this line in a spiral
direction. In one of these slots I place the valve for distributing the motive fluid
to the ends of the main cylinder of the pistons referred to and in the other slot a
stud fixed to the cylinder for the purpose of giving a semi-rotating motion to the
sleeve referred to. By means of the fixed stud and the two slots in the sleevè the
proper and necessary movement of the valve is obtained.
Dated this 27th day of June 1889.
WILLIAM MCNEILL.
COMPLETE SPECIFICATION.
Improvements in Rock Boring Machinery.
I, WILLIAM MCNEILL, of 29 North Villas, Camden Square, London, Mining and
Mechanical 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 :-
For the purpose of obtaining reciprocating motion of the piston and boring tool
in rock boring machinery, I place between two pistons on a piston rod within the
main cylinder a sleeve or cylinder in one piece.
On this sleeve, which I term the valve sleeve I make two slots, the direction
of these slots is not coincident, with the axial line of the pistons but departs right
or left of this line in a spiral or curved direction. In one of these slots, which I
designate the valve slot, I place the valve for distributing the motive fluid to the ends
of the main cylinder of the pistons referred to, and in the other slot which I
designate the stud slot a stud fixed to the cylinder for the purpose of giving a
semi-rotating motion to the sleeve referred to.
By means of the fixed stud and the valve and stud slots in the valve sleeve the
proper and necessary motion of the valve is obtained.
In order that my invention may be fully understood, I shall now proceed more
particularly to describe the same, and for that purpose shall refer to the several
figures on the annexed sheets of drawings, the same letters of reference indicating
corresponding parts in all the figures.
Figure 1. is a longitudinal section through the centre of the machine.
Figure 2. is a plan with cover plate F. removed.
Figure 3. is a transverse section through Z. Z looking towards that end of the
piston rod which carries the drilling tool.
Figures 4 & 5. show two views of the valve sleeve the former showing the valve.
slot and the latter the stud slot.
Figures 6, 7, & 8. show another method of construction figure 6 being a transverse
section figure 7 a longitudinal section and figure 8 a plan.
D

page_text: A A is the cylinder of the machine, G. the piston rod H & I. pistons fitting withi
the cylinder and free to move in it ; one or both of these pistons may be strewed on
to the piston rod or otherwise fitted to it in order that the valve sleeve J. may be
placed upon the piston rod between them, so that the piston rod can rotate within
the valve sleeve J but cannot move in an axial direction without carrying the valve
sleeve with it. B, & C. are ports for admitting and exhausting the motive fluid
from the ends of the cylinder A A. The ports B & C. communicate with the
valve face over which the valve E slides by means of the recesses B & C and the
ports
B & C respectively. The recesses B & C are covered over and kept tight
by means of the cover plate F. This cover plate is merely a convenience of manu-
facture, and may be entirely done away with by casting the ports wholly within
the body of the cylinder or the machine may be manufactured in the manner shown
in Figures 6, 7 & 8 from which it will be seen that the face over which the valve
travels is fitted to the machine and has, cast within it, the ports and
cavities B2, B¹; C², C¹.
D is the exhaust port communicating with the atmosphere directly in Figure 6 and
through a hole P in the cover plate F. in Figure 3.
The valve E is an ordinary slide valve L & K. are the appertures for the supply of
the motive fluid.
The cylinder A A is bored with a recess Q in which the valve E moves cir-
cumferencially, being operated by the cylindrical hollow valve sleeve J as it is carried
to and fro between the pistons H & I. The valve sleeve J has cut or formed upon it
two slots M & N. Into the slot M the back of the valve E is placed and this I term
the valve slot which is shown in Figure 4 the valve sleeve J. being placed in a
position for showing this slot. Into the slot N, a stud O is fitted which may be either
fixed to the cylinder as shown in Figures 1 & 3 or cast in one piece with the cylinder
as shown in Figures 6 & 7. The slot N term the stud slot and in Figure 5 the
valve sleeve is turned round so as to show this slot.
The slots, M & N are not coincident with the axial line of the pistons but depart
therefrom in a spiral or curved direction as shown in Figures 4 & 5.
By virtue of the slot N and the stop or stud O which is placed in it the valve
sleeve J. is caused to vibrate as it is carried to and fro between the pistons H & I.
It will thus be seen that the valve E has simultaneously impressed upon it two.
movements, viz. :-that due to the vibration of the valve sleeve and that due to the
curved nature of the slot M in which the back of the valve E is itself placed, as the
piston rod and pistons reciprocate.
In figure 3. the valve is shown at the extremity of its stroke.
It has opened
the port to pressure and the port B2 to the exhaust and in consequence the piston
will be propelled forward to the blow; and when it has arrived at the end of its stroke
the vibration of the valve sleeve J. and the curved nature of the slot M will have
caused the valve E to have been reversed and to have thereby opened to pressure the
port B, B1, B2 and to exhaust the port C, C, C and so causes the piston to be carried
back ready for another blow.
The piston is partially rotated at every return stroke by any of the ordinary well
known ways.
It is free to rotate within the sleeve without interfering with the vibration of the
sleeve.
The machine is mounted and fed forward to its work by any of the well known
methods.
Having thus 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.
(1) The use of a valve sleeve formed in one piece with stud and valve slots shaped
thereon for imparting movement to a distributing valve substantially as described and
illustrated.
(2) The use of a distributing valve placed directly in the valve slot substantially as
described and illustrated.

page_text: (3) The use of portways in the cylinder for admitting and exhausting the motive
finid from the ends of the cylinder substantially as described and illustrated.
(4) The construction of a loose cylindrical valve face with valve ports substantially
as described and illustrated.
(5) The casting of the stud for operating the valve sleeve in one piece with the
cylinder substantially as described and illustrated.
(6) The manufacture and use of the improved apparatus described and illustrated
in the accompanying drawings.
Dated this 26th day of March 1890.
WILLIAM MCNEILL.