IMPROVE- MENTS IN MEANS AND APPARATUS FOR DRESSING STONE
Year: 1878

page_text: LETTERS PATENT to Edward Alfred Cowper, of No. 6, Great George Street,
Westminster, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN MEANS AND APPARATUS FOR DRESSING STONE."
Sealed the 14th May 1878, and dated the 3rd January 1878.
PROVISIONAL SPECIFICATION left by the said Edward Alfred Cowper at the
Office of the Commissioners of Patents on the 3rd January 1878.
EDWARD ALFRED COWPER, of No. 6, Great George Street, Westminster, in the
County of Middlesex. " IMPROVEMENTS IN MEANS AND APPARATUS FOR DRESSING
STONE."
According to my present Invention I dress stone by means of apparatus of the
following kind:-A reciprocating piston working very quickly in a small cylinder,
actuated by steam or compressed air, carries the chipping tool to dress the stone,
the cylinder and tool being mounted on longitudinal and transverse slides, so that
being moved by hand or by power it is caused to pass slowly over the surface of
the stone to be dressed, so that the tool which does not rotate like a rock drill may
operate on the stone, and at each passage cut a certain width of the stone down to
a given level or to a given line, the tool being prevented from descending below a
certain depth or cutting too far in by a fixed or adjustable stop that receives the
blow if the stone does not.
Instead of arranging the cylinder and tool to slide in both directions the tool
may be fitted to slide in the one direction, whilst a table carrying the stone may be
slid in the other direction.
By the above arrangements the whole surface of the stone to be dressed is com-
manded by the cutting tool. The small cylinder is by preference steam jacketted
when steam is used, or the steam may be superheated so as to prevent condensation
in the cylinder, as a mixture of steam and water does not work the piston quickly.
The steam or air is brought to the cylinder through flexible pipes or pipes with
elbow joints.

page_text: The stroke of the piston may be varied as required by opening or closing certain
passages for the steam or air, or by admitting more or less steam or air.
The stone is by preference placed on a turnplate for the purpose of turning it
round to dress it in different directions or to dress its surface to a curve, as for
columns and other curved work. The turnplate or table is provided with one or
more plates attached at right angles or other angle to the same, or with a plate
adjustable at various angles; also with centres or chucks, like those of a lathe for
the purpose of fixing or supporting the stone in any desired attitude, or turning it
more or less round to receive the action of the tool.
When the tool is mounted over the stone it is preferred so to arrange its guides
that they can be moved entirely out of the way, so that the stone may be lifted by
a crane or other overhead tackle.
.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Alfred Cowper in the Great Seal Patent Office on the 2nd
July 1878.
EDWARD ALFRED COWPER, of No. 6, Great George Street, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN MEANS AND APPARATUS FOR DRESSING
STONE."
According to my present Invention I dress stone by means of apparatus of the
following kind: A reciprocating piston working very quickly in a small cylinder,
actuated by steam or compressed air, carries the chipping tool to dress the stone,
the cylinder and tool being mounted on longitudinal and transverse slides, so that
being moved by hand or by power it is caused to pass slowly over the surface of
the stone to be dressed, so that the tool, which does not rotate like a rock drill, may
operate on the stone, and at each passage cut a certain width of the stone down to
a given level or to a given line, the tool being prevented from descending below a
certain depth or cutting too far in by a fixed or adjustable stop that receives the
blow if the stone does not,
Instead of arranging the cylinder and tool to slide in both directions the tool
may be fitted to slide in the one direction, whilst a table carrying the stone may be
slid in the other direction.
By the above arrangements the whole surface of the stone to be dressed is com-
manded by the cutting tool. The small cylinder is by preference steam jacketted
when steam is used, or the steam may be superheated so as to prevent condensation
in the cylinder, as a mixture of steam and water does not work the piston quickly.
The steam or air is brought to the cylinder through flexible pipes or pipes with
elbow joints.
The stroke of the piston may be varied as required by opening or closing certain
passages for the steam or air, or by admitting more or less steam or air.
The stone is by preference placed on a turnplate for the purpose of turning it
round to dress it in different directions or to dress its surface to a curve, as for

page_text: columns and other curved work. The turnplate or table is provided with one or
more plates attached at right angles or other angle to the same, or with a plate
adjustable at various angles; also with centres or chucks like those of a lathe, for
the purpose of fixing or supporting the stone in any desired attitude, or turning it
more or less round to receive the action of the tool.
When the tool is mounted over the stone it is preferred so to arrange its guides
that they can be moved entirely out of the way, so that the stone may be lifted by
a crane or other overhead tackle.
Fig. 1 is a pran, Fig. 4 afront elevation, g
constructed according to my Invention.
a is a block of stone being dressed, standing upon the turnplate b, which rests
upon the circular curb or bed plate c; c¹ is a strong bed plate firmly bolted to or
cast with the curb c, and forming with it the foundation of the machine; d, d¹, are
hollow cast-iron standards or posts turned parallel; and e, e¹, are sockets fitted to
slide up and down upon these posts, which may be steadied by the inclined
stays 2, 2; f is a hollow turned horizontal bar, fitting at its two ends into the
sockets e, e¹ ;g is a socket fitted to traverse along the horizontal bar f, and carrying
the cylinder h. The chipping tool i is fixed in the piston rod d³, and passes
through a hole in the end of the buffer box j, as shewn in Fig. 7, which is a longi-
tudinal section to an enlarged scale of the buffer box.
To give facility for adjusting the angle of the tool to the work it is advantageous
to provide on the under side of the cylinder h a circular flange k turning on a
central pin, and having slotted holes for the bolts, by which it is fixed to a sliding
plate L.
To provide for the adjustment of the distance of the cylinder and tool from the
stone the plate is mounted on slide rest guides m on the upper face of the
socket g, and is provided with two lugs enclosing a nut n (shewn by dotted lines
in Figs. 1 and 3) working on the screw o. By turning the screw o the cylinder
with its tool is made to approach to or recede from the axis of the turntable so as
to suit the size of the stone to be worked, and adjust the depth of the cut.
The longitudinal motion of the tool along the face of the stone is obtained by
means of the pinion p mounted on the socket g working into the rack in the
bar f. The pinion p can be turned by hand or may be driven at suitable speed by
power; also & traversing screw and nut may be substituted for the rack and
pinion.
The transverse motion of the tool over the face of the stone, or vertical motion of
the cylinder and tool, is obtained by raising and lowering the horizontal bar f and
Bockets e, e¹, by means of screws 8, 81, inside the posts d, d', passing through nuts
on brackets or arms t, t', which are attached to the sockets e, e¹, and project inwards
into the hollow posts. One of the screws is turned by means of a handle at the
top, and the rotation is communicated to the other by the bevil gearing u, u, u¹, u¹,
and the shaft v.
The turnplate b has numerous holes to take pins or bolts for fixing or holding
the stone firmly in position. The turnplate 6 rests on the curb c so as to give
perfect steadiness when the machine is at work.
When it is desired to turn the stone round to present another face to the tool
the turnplate is slightly lifted off the curb by raising the bar or lever won one end
of the shaft w¹, which causes an eccentric or cam at the other end of the shaft w₁
to slightly lift the central pin x, upon which the turnplate carrying the stone is
then free to revolve. y is a spring catch, which holds the turnplate by entering
one or other of the holes b' in its circumference, which may be 90° apart for rect-
angular work, 45° for octagons, or separated by other angles, according to the form
of stone dealt with.

page_text: Fig. 4 shews a table chuck or vertical plate bolted on the turnplate for fixing,
on their edges, stones, such as copings and like forms, whilst their faces are being
dressed, wedge-shaped packing, of wood or other suitable material, being employed
when required to block the stone out of the vertical.
Figs. 5 and 6 shew hinged plates attached to the turnplate, which may be
used for the greater facility of adjusting the stone at any angle required. That
shewn in Fig. 5 is suitable for angles approaching the vertical, and that shewn
in Fig. 6 for those approaching the horizontal. In the latter case wedges of
wood, stone, or other suitable material are inserted between the angle plate and the
turnplate.
In another form of the machine the horizontal bar f carries the slide, cylinder,
and tool over the top of the stone to be dressed, in which case the slides d, d', are
placed horizontally.
In place of the socket with the slide, cylinder, and tool sliding on the bar f,
they are fixed to the bar f, which itself slides or runs upon rollers attached to the
sockets e, el, it being then made of a proper section for so working.
The cylinder may be of the kind used in the machines commonly known as rock
drills, but without rotation being imparted to the tool, and may be of any known
construction.
The buffer box j, of which Figure 7 shews a longitudinal section, is securely
fixed to the cylinder, and has a disc or plate a³ screwed into it to form an adjustable
stop for the piston rod to limit the stroke, a buffer formed of a thin disc b² of
india-rubber, leather, or other suitable material being inserted to slightly soften the
blow. The shank of the tool i, which is considerably smaller in diameter than the
piston rod d², passes through a hole in the said plate and buffer.
In order to prevent dirt and grit from getting to the slide bar fit may be
covered by two bags or sleeves of canvas, cloth, or other suitable material attached one
at each end to the sockets e, e¹, whilst the other ends are attached to the sliding
socket g, the sleeves having sufficient length to allow of the socket working its full
stroke either way. They may be conveniently kept in shape by a few cane or
wire rings fixed at intervals inside them. The posts d, d², may be protected in the
same manner. The turnplate by its construction has its bearing surfaces entirely
protected from dirt. The piston rod is also completely housed within the buffer box,
so that no working part is exposed to grit.
Having thus described the nature of my Invention and in what manner the same
is to be performed, I claim, dressing stone by means of a reciprocating piston
worked by steam or compressed air, and carrying a chipping tool, arranged so as to
traverse over the surface of the stone, and having its stroke limited by a stop or
buffer, substantially as herein described.
In witness whereof, I, the said Edward Alfred Cowper, have hereunto set
my hand and seal, this Twenty-ninth day of June, in the year of our Lord
One thousand eight hundred and seventy-eight.