IMPROVEMENTS IN MACHINERY OR APPARATUS FOR CUTTING, DRESSING, PLANING, AND SHAPING STONE
Year: 1877

page_text: LETTERS PATENT to John Dickinson Brunton, of Kentish Town, in the County
of Middlesex, Engineer, for the Invention of "IMPROVEMENTS IN MACHINERY
OR APPARATUS FOR CUTTING, DRESSING, PLANING, AND SHAPING STONE"
Sealed the 22nd September 1877, and dated the 29th March 1877.
PROVISIONAL SPECIFICATION left by the said John Dickinson Brunton at
the Office of the Commissioners of Patents on the 29th March 1877.
JOHN DICKINSON BRUNTON, of Kentish Town, in the County of Middlesex,
Engineer. "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR CUTTING, DRESSING,
PLANING, AND SHAPING STONE."
My Invention relates to improvements in the method of applying circular cutters
to the cutting, dressing, planing, and shaping of stone, and consists of a peculiar
mode of imparting to circular cutters a positive rotatory motion around their own
axes, independently of any rotation which they might derive from their contact
with the stone.
In carrying out my Invention I fix on a spindle a chuck carrying one or more
circular cutters which can be rotated on their own axes, and I impart to this spindle
and chuck a revolving motion. On the arbors of the cutters I place toothed wheels,
and in the interior of the chuck, so as to gear into the wheel on the arbor of the
cutter, or if there, be more than one, then into the wheels on the arbors
of all the cutters carried by the chuck I place another wheel fixed upon a
shaft. I drive both the chuck spindle and the said shaft by belts or toothed
gear, or any other convenient means, but independently one of the other, and I
so proportion their relative speeds that there shall be communicated to the circular
cutters, by means of the said shaft and the toothed gear before mentioned, such
a positive rotation as shall cause their cutting edges when in contact with the
stone, and in the operation of dressing it, to roll and not to rub on its surface; or
I fix in a suitable holder a circular cutter or cutters mounted upon an arbor or
arbors, so as to be free to rotate on their own axes; and on the said arbor or arbors
[Price 6d,]

page_text: I place toothed wheels, to which I impart rotatory motion by means of other
toothed wheels gearing into them, and deriving their motion from a rack or friction
bar or other convenient means.
SPECIFICATION in pursuance of the conditions of the Letters Patent, and of
an Order of the Lord Chancellor, filed by the said John Dickinson Brunton in
the Great Seal Patent Office on the 17th October 1877.
JOHN DICKINSON BRUNTON, of Kentish Town, in the County of Middlesex,
Engineer. "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR CUTTING, DRESSING,
PLANING, AND SHAPING STONE."
My said Invention relates to improvements in the method of applying circular
cutters to the cutting, dressing, planing, and shaping of stone, and consists of a
peculiar mode of imparting to circular cutters a positive rotatory motion around
their own axes independently of any rotation which they might derive from their
contact with the stone.
In carrying out my said Invention I fix on a hollow spindle a hollow chuck
carrying one or more circular cutters which can be rotated on their own axes, and
I impart to this spindle and chuck a revolving motion. On the arbors of the cutters
in the interior of the chuck secure toothed wheels, which are caused to gear with
a central wheel fixed upon a shaft passed through the hollow chuck spindle, and
supported in a footstep bearing in the interior of the chuck. I drive both the chuck
spindle and the said internal shaft independently one of the other by belts or toothed
gear, or any other convenient means, and I so proportion their relative speeds that
there shall be communicated to the circular cutters, by means of the said shaft and
the toothed gear before mentioned, such a positive rotation as shall cause their
cutting edges when in contact with the stone, and in the operation of dressing it, to
roll and not to rub on its surface.
And in order that my said 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 Sheet of Drawings, the same letters of referenco indicating
corresponding parts in all the Figures.
Figures 1 and 2 of the accompanying Drawing represent respectively a section
and plan of one modification of cutter chucks constructed according to my
Invention.
Figure 3 is a section of a portion of a chuck constructed according to another
modification.
And Figure 4 is a section showing a further modified construction of chuck
intended more particularly to be employed in cutting mouldings and for otherwiso
shaping stone.
Referring to Figures 1 and 2, A is the body of the chuck, which in the example
shewn is constructed to carry three cutters, but which may be arranged to carry
any other desired number; it is made hollow, and secured to the lower extremity
of a hollow shaft B, having keyed thereon a driving pulley C, by means of which
rotatory motion is imparted to the chuck from any suitable prime mover.
The cutters D (one only of which is shown in the Drawing) are cach nounted on
a separate inclined spindle or arbor E, fitted to rotate in bearings F, F1, in the
body A of the chuck, a ring of felt a being provided in the top bearing F for the
purpose of excluding dust. The back pin b takes the thrust of the spindle E. On
each of the cutter arbors there is keyed a toothed wheel G in gear with a corre-
sponding central wheel H, fast on the lower end of a vertical shaft I, which is passed
through the hollow shaft B, and supported in a footstep bearing K fitted in the
interior of the chuck. This shaft I is actuated from any suitable prime mover by
means of a strap passed round a pulley L, fitted on the shaft outside the chuck, or

page_text: by means of gearing or otherwise, and transmits a positive motion through the
wheels H and G to the whole of the cutters simultaneously.
The pulley L or toothed wheel, as the case may be, is fitted on the shaft I in
such a manner as to be capable of being readily removed and replaced by a pulley
or wheel of a different diameter, for the purpose of accommodating the rate of
rotation of the cutters to their varying size, it being obvious that as the cutters
become less in diameter by wear their rate of rotation must be increased in order
to maintain their purely rolling action upon the stone.
The cutters D may be rigidly fixed on their arbors or connected thereto in any
suitable manner. The following arrangement has however been found convenient
in practice: On the arbor E there is formed a collar M, against which the back of
the cutter is caused to bear by a nut N, screwed on to the extremity of the arbor,
and acting against a conical ring O fitted into a correspondingly tapered hole formed
in the centre of the cutter. By screwing the nut N on to the arbor E the ring O will
be forced into the hole in the cutter, and jamb the latter against the collar M, thereby
holding the cutter firmly in position.
The chuck, with its cutters arranged in the manner herein-before described may
be mounted in any suitable framing so as to admit of the required rotatory motions
for operating upon the surface of the stone.
I proportion the relative speeds of the chuck A and the shaft I so that a positivo
motion shall be imparted to the cutters through the gearing H, G, which will cause
their cutting edges when in action to roll and not to rub on the surface of the
stone.
The stone to be operated upon, which may be carried upon any suitable table or
support, is traversed beneath the cutters whilst they are in motion; the cutters as
they rotate chip the rough surface from the stone as it passes beneath them, and
produce a flat and comparatively smooth surface thereon.
In lieu of arranging the axis of the chuck vertically, as shewn in the Drawing, it
may be placed horizontally, and the cutters caused to act upon the vertical face of
the stone, which would be passed in front of the cutters instead of beneath them, as
in the arrangement herein-before described.
The arbors of the cutters in the chuck shewn in Figures 1 and 2 are arranged
with their axes converging towards a point situate below the face of the chuck, the
point of contact d of the cutter with the stone being towards the outside of the
chuck. I sometimes however arrange the cutter arbors with their axes converging
towards a point situate above the chuck, as shewn in Figure 3, the point of contact
d of the cutter with the stone in this case being towards the centre of the chuck.
In this case the face of the stone to be dressed must not be larger than will be con-
tained in the circle described by the lowest point of the cutters. The stone is
placed within this circle, and the cutters take off the rough surface when the stone
leaves the circle travelling in a line at right angles to the axis of the chuck.
In order that the cutters may roll in their action upon the stone, the central
wheel H, in gear with the wheel G, can be stationary, or need only have a slow
compensating rotation as the cutters wear, the rotating of the chuck alone causing
the cutters to rotate in the right direction.
In the arrangement, Figure 1, the central wheel H, if stationary, would cause the
cutters to rotate in the wrong direction, and it must therefore be driven at such a
high speed in the direction of the rotation of the chuck as to cause them to rotate
in the right direction, that is to say, to give them a rolling action upon the stone.
By dispensing however with the central wheel H in Figure 1, and substituting a
ring with internal teeth, in which the wheels G gear, the same effect can be obtained
as in the arrangement, Figure 3.
In the modification illustrated by Figure 4, which I employ for cutting mouldings,
the cutter arbors E are actuated in a similar manner to those in the arrangements
herein-before described, but in order to admit of the chuck being adjusted so as to
form any required moulding it is mounted in a holder which is capable of receiving
a horizontal to-and-fro motion, as well as a vertical or rising and falling motion,

page_text: whilst the stone, under operation, in addition to be traversed longitudinally, as
herein-before described, is mounted on centres so as to be capable of adjustment
around the same as required.
The cutting edges of the cutters are arranged to project beyond the body of the
chuck in order to admit of them forming concavities or recesses in the stone, and
the gearing G and H, for imparting the positive motion to the said cutters is
arranged at as great a distance from the cutters as is practicable, in order that the
enlargement provided in the body of the chuck for the reception of the said gearing
shall not come in contact with the stone so as to obstruct the advance of the cutters
or in any way affect their required motions.
For the purpose of lubrication I fill the chuck with soap and water, and I provide
a recess c in the lower bearing F of the cutter arbors, in which recess I fit a ring of
leather or other suitable packing in order to prevent leakage of the lubricant.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the manner in which the same is or may be used or carried into offect, I
would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to ine by the herein-before in part recited
Letters Patent is,―
First. The imparting to circular cutters a positive rotation by means of gearing
arranged in the interior of the chuck, substantially as herein-before described and
illustrated by my Drawings.
Secondly. The combination with a hollow chuck carrying a circular cutter or
cutters having a positive motion imparted thereto by gearing situate in the interior
of the chuck of means for controlling and adjusting the speed of the cutter or cutters
relatively to the speed of the chuck, substantially as herein-before described.
In witness whereof, I, the said John Dickinson Bruntou, have to this my
Specification set my hand and seal, this Sixteenth day of October, One
thousand eight hundred and seventy-seven.