Improvements in and Apparatus for Cutting Stone or like Materials.
Year: 1898

page_text: PROVISIONAL SPECIFICATION,
Improvements in and Apparatus for Cutting Stone or like Materials.
I, FARQUHAR MATHESON MCLARTY, of 52, Forsyth Street, Greenock, in the
County of Renfrew, Scotland, Mechanical Engineer, do hereby declare the nature
of this invention to be as follows:-
The object of my invention is to effect the cutting of stone or like material in
circular straight, or other, lines, in a manner that will overcome many of the
difficulties which have hitherto existed in connection with the execution of such
work.
In the case say of jumping a hole in rock by the ordinary methods, the tool
is subjected to shock and in consequence frequently breaks; it is moreover sub-
jected to uneven wear, because the outer edges of the chisel, or jumper, have
more work to do than have the parts towards the centre, so that the tool rapidly
becomes useless and frequent renewals are necessary while there is a constant
tendency to the lessening of the diameter of the hole owing to the extra wear on
the outer edges of the tools, with the result that when a hole of small diameter
would be large enough for a required purpose, it is necessary, especially with
holes of considerable depth, to begin with a large hole so as to be able to finish
at the desired diameter.
The alternative methods of separation now in use have other defects, all
separating the material in a direction that admits of the material behind the
point of attack supporting the material at the said point and thus retarding the
work of separation.
According to my invention I provide means for separating any desired part
of the stone, or the like, whether it be in portable pieces or in place as fixed
rock, and so that the stone or the like is attacked in the direction in which
its cohesive character is most vulnerable, without subjecting the cutting tools to
shock, and, in a manner which reduces their tendency to wear hitherto experienced
in this class of work, while my method of applying the force necessary for
separation is such that a comparatively small amount of power suffices for boring
large holes, and for cutting up large blocks of stone or the like into pieces
suitable for building, or other purposes in which stone or the like is required to
be of specific form and dimensions.
Although the aforesaid principles govern the work of separation and the
application of the force, the details by which these principles according to this
invention are applied can be varied in detail as can likewise the methods of
removing the débris. but I will describe one application of the invention in
order to make the nature thereof clear.
The separating tools according to my invention consist of circular toothed
cutters revolving on their centres while travelling round a circle or in a straight
or other line as required. The teeth bear on the stone or other material, and the
load, or force, hears on the circular cutters very much as the load on a cart is
borne on the wheels thereof. The effect is, that when a load is applied and

page_text: motion given, the teeth sink into the stone, or the like, one after another and
break it, bit by bit. The slicing effect being practically on a line with the
direction of the force, it follows that in the case of a vertical bore the action of
the teeth is to slice downwards, separating the bits they bear on, one side of each
of which has, by the action of the cutter, been cut away so that there is nothing
to support the part attacked, which, therefore, is easily separated. In the case
of a bore hole a series of such cutters extends from the centre to the circumference,
one set on each side of the centre, each tooth in turn doing its share of the work
to be immediately followed by the next and so on, one of the advantages being
that each cutter has a multiplicity of cutting edges and, from that cause alone,
there is greatly increased durability and a great number of lines of such wheels
can be used the effect just mentioned not being limited excepting by the room
there may be to work in. But besides the durability obtained from these
features of the invention, there is the further lessening of wear from the attacking
of the stone or the like in the direction of least resistance to separation.
In the case of a bore, the diameter of each cutter can be made so that its circum-
ference and the circumference of the line round which it cuts, differ in a degree
that will cause each tooth to continuously change its point of attack, the object
being to secure the easy removal of the ridges which the action of the cutter
would be apt to leave if the teeth were allowed to come into the exact point which
had been previously attacked. This change can be effected also by making the
pitch of the teeth uneven, and in short, the arrangement can be such that every
particle of the stone or the like can be in turn attacked with any desired force
without shock and with any desired size of cut.
In the case of cutting in lines other than circular, means are provided for
obtaining the foregoing advantages, and with equal ease.
The smallness of the force required for working my aforesaid cutters is self
evident not only because of the reduction of the resistance to separation, but also
for the reason that any loaded machine resting on wheels hearing on a hard
surface, can be moved by the application of a force representing only a very
small fraction of the load.
I provide means whereby the grit is cleared away. I may use for this purpose
fluids under pressure, brushes, scrapers, or the like, and elevators where required,
according to the nature of the work.
In cutting in other than circular lines the work may be effected either by a
backward and forward action, or by action in one direction only, the cutters being
held out of action on the return stroke as may be desirable according to the
nature of the work to be done, and in circular action the teeth can be made to
cut in either direction, or more especially in one direction as may be desired.
Dated this 21st day of February 1898.
JOHNSONS & WILLCOX.
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in and Apparatus for Cutting Stone or like Materials.
I. FARQUHAR MATHESON MCLARTY. of 52, Forsyth Street, Greenock, N.B.,
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 ascer-
tained in and by the following statement:-
The object of my invention is to effect the cutting of stone, or like materials,
(that is to say, materials which have a small degree of elasticity and whose tensile

page_text: strength is materially less than their crushing strength) in circular, straight, or
other lines, in a manner that will overcome many of the difficulties which have
hitherto been experienced in connection with the execution of such work.
In the case, say, of jumping a hole in rock by the ordinary methods the tools,
or jumpers are subjected to shock of such violence that they frequently break.
They are, moreover, subjected to uneven wear, because the outer edges of the
chisel, or jumper, have more work to do than have the edges nearer to the
centre, so that the tool, or jumper, rapidly becomes useless, and frequent
renewals are necessary, while there is also a lessening of the diameter of the hole
owing to the extra wear on the outer edges of the tools, or jumpers, so that,
when a hole of a given diameter is required, it is necessary, especially in boring
holes of considerable depth, to begin with a larger hole than is required so as to
be able to finish at the desired diameter.
The methods of separation hitherto in use have other defects, all separating
the material in a direction that admits of the material forward of the point of
attack (that is to say, all the material that is in front of the tool) supporting the
material at the point of attack and thus retarding the work of separation.
According to my invention I provide means for separating any desired part
of the stone, or the like, (I will hereinafter refer to it as stone for the sake of
simplicity), whether it be in portable pieces, or in place as fixed rock, so that the
stone is attacked in the direction in which its power of cohesion is most vulner-
able, without subjecting the tools to injurious shock, such as that herein before
referred to in the case of jumpers, and in a manner which reduces the wear of
such tools hitherto experienced in this class of work while my method of apply-
ing the force necessary for separation is such that a comparatively small amount
of power suffices for boring large holes and for cutting up large blocks of stone
into pieces suitable for building, or other purposes, in which the stone is required
to be of specific form and dimensions.
:
Although according to my invention, the main principles herein before explained
govern the work of separation, and the application of the force, the details by
which these principles according to my invention are applied can be varied as
can also the methods of removing the debris, but I will describe some applications
of the invention in order to make clear the nature thereof and the manner in
which it can be performed.
The separating tools, according to my invention, consist of circular toothed
cutters capable of rotating on their centres whilst being traversed, in a circle or in
a straight, or in other, line, as required, the said teeth hearing on the stone, and
the load, or force, bearing on the cutters, very much as the load on a cart is
borne on the wheels thereof, so that the effect is, that when a load is applied and
traversing motion is given to the cutters, the teeth sink into the stone one after
another and break it, bit by bit. The slicing effect being practically on a line
with the direction of the load, or equivalent force, it follows that in the case of a
vertical bore, the action of the teeth is to slice downwards, separating the bits to
the rearward of them, one side of each of which has, by the action of the cutter,
been cut or wedged, away so that the part attacked is easily separated. In the
case of a bore hole a set or sets of such cutters is or are used (one set extending
from the centre to the circumference) preferably not less than one set on two
opposite sides of the centre, each tooth in turn doing its share of the work to be
immediately followed by the next, and so on, one of the advantages being that
each cutter has a multiplicity of cutting, or wedging edges, and from that cause
alone there is (in comparison to the methods hitherto used for boring) greatly
increased durability. A small or a great number of lines of such cutters can
be used, the effect described not being limited excepting by the room there may
be to work in. Besides the durability obtained from the aforesaid features there
is the further lessening of wear from the attacking of the stone in the direction
of least resistance to separation.
In the case of boring a hole the diameter of each cutter can be made so that

page_text: its circumference, and the circumference of the line round which it cuts differ
so that each tooth continuously changes its point of attack the object being to
secure the easy removal of the ridges which the action of the cutter would be
apt to leave if the teeth were allowed to come at each rotation onto exactly the
same point which had been previously attacked thereby. This change can be
effected also by making the teeth of the cutters travelling in the same line, of
uneven pitch, and in short, the arrangement can be such that every particle of
the stone can be in turn attacked with any desired force without injurious shock
and with any desired size of cut.
The power required for working cutters according to my invention is small in
comparison to the power required for working according to the methods hitherto
in use not only because of the reduction of the resistance to separation, but also
because any loaded machine resting on wheels bearing on a hard surface can be
moved by a force representing only a small fraction of the load.
A set of cutters for boring will preferably (though not necessarily) be of vary-
ing diameters. They preferably vary in diameter because the further the opera-
tive part of each cutter is from the centre the longer will be the line on which
it rotates. Hence in order to give each tooth a more nearly equal amount of
work to do the outer cutters should be larger in diameter than those nearer to
the centre in proportion to the relative length of the path on which they act.
Of the various means of clearing away the girt from the cutters, namely fluids
under pressure, brushes, scrapers, elevators or the like, the use of water under
pressure is preferred, as it, when directed on to the cutters clears them instantly,
and has the advantage of keeping the cutters free in action so that wear on the
cutters, from the girt being pressed between them, and the stone being cut is
prevented, the separating effect being obtained from the direct action of the
cutters themselves in the manner described.
In cutting in other than circular lines the teeth may be made to act, by either
backward or forward action, or by both as may be desirable according to the
nature of the work to be done and in cutting in a circular direction the teeth can
be made to cut in either direction, or more especially in one direction as may be
desired.
The great utility of my invention in cutting large blocks of stone into pieces
suitable for building or other purposes in which stone is required to be of specific
form and dimensions will be understood by comparison with the methods hitherto
used in such work. The methods of cutting hitherto used are such that the tools,
besides having to overcome the adhesion of the particles to their immediate neigh-
bours have to overcome the much greater resistance offered by the material for-
ward of the point of attack whereas according to my invention the only resistance
to separation is that due to the adhesion of the particles to their immediate
neighbours which is extremely small as compared to the crushing strength of
stone which crushing strength is opposed to the cutting action in the methods
hitherto in use.
What I have stated regarding the characteristics of my invention in relation to
boring holes applies also to cutting blocks of stone in straight, or other lines, for
instance, in dividing a block of stone into straight slabs the only difference is
that the cutters travel in straight lines whereas in hole boring they travel in
circles. In all cases there are the following simultaneous movements of the
cutters, namely the movement by which the cutters are carried in the desired
direction as for instance, in the direction of the arrow in the diagram Figure 1^
of the accompanying drawings the rotatory movement of the cutters being in the
direction of the arrow y by which (in conjunction with the first named move-
ment) a new point of contact is obtained and the movement of each tooth at the
moment of contact which latter movement is obtained by a combination of the
first named movements, with the movement of the feed of the cutters in the direction
of the arrow . In the said diagram represents the part of the stone which has
been operated upon and w represents the part which is to be operated upon. The

page_text: result of the several movements is a thrusting action of each tooth nearly at right
angles to the line in which the axis of the cutter is travelling so that the separating
effect of each tooth may be likened to the action of a wedge, or tapered chisel,
when it is driven into stone at a point in close proximity to the edge thereof
the corresponding edge (u in the diagram) according to my invention, being formed
by the preceding tooth, and as the teeth follow each other, the stone is separated
by breaking it bit by bit. By these means the separation can be effected with
such a degree of nicety that a practically even and smooth surface can be pro-
duced while by suitably pitching and angling the teeth and increasing the ratio
of feed, even and rough surfaces can be produced as desired.
The foregoing explains the principals of my invention and in order that its
practical application may be clearly understood, I will refer to the accompany-
ing drawings in which are illustrated by way of example methods of applying
the cutters to machines whose motions fit them to bore, divide, plane, or mould
as required.
Figures 1 and 2 shew in elevations at right angles to each other a cutter in
its holder (with part of the blade on which the holder is mounted) for dividing
stone to the depth A.
Figure 3 shews in elevation a series of such cutters in their holders, and the
edge view of the blades on which the holders are mounted, and also part of the
tool bar to which the said blades are secured, and means for securing the blades
to the tool bar, so that they can be adjusted, the cutters being shewn as cutting
straight edges on a corresponding number of slabs of stone.
Figures 4 and 5 show, in elevations at right angles to each other, double and
single cutters, holders and blades, and part of the tool bar, with means for
adjusting and fixing the blades, the arrangement being suited for dividing stone
to any depth allowed by the blades by the action of small cutters which entirely
enter the stone operated on, clearing the way for the blades, and which produce
two plane surfaces in each division.
Figures 6 and 7 show (on a larger scale than that of Figures 4 and 5) a double
cutter, holder therefor, and part of a blade, the figures being elevations at
right angles to each other.
Figures 8 and 9 shew a single cutter with its holder and part of a blade, the
figures being also elevations at right angles to each other.
Figure 10 shews in elevation three moulding cutters with their holders and
blades, and part of the tool bar, the said cutters being raised out of contact after
having moulded the edges of six blocks of stone. Figure 11 shews six cutters
(with their holders and blades and part of the tool bar) in the act of producing
a plane surface (or if desired a series of plane surfaces or steps) on a block of
stone. Figures 12 and 13 shew, in elevation and sectional plan respectively, a
set of cutters arranged for boring holes. In all the figures corresponding parts
are marked with the same letters of reference.
For dividing blocks of stone, and at the same time producing even faces thereon.
and also for moulding the edges of stone, or producing a plane surface or plane
surfaces on an outside face of a block of stone the apparatus consists principally
of the cutters * holders a² therefor, adjustable blades a for carrying the cutter
holders, means of fixing the blades at any desired position within the scope of the
tool bar, and the tool bar B, which is made so as to be attachable to, and control-
able by, a holder in any machine having a reciprocating motion, and means of
actuating the feed according to the direction in which it is desired that the
teeth of the cutters shall act.
For boring holes the apparatas consists principally of the cutters holders
therefor secured to a tubular or solid rod E (Figures 12 and 3) for connecting
the holder to any machine having a rotary motion, and means of feeding in the
direction in which boring is to be done.
The cutters may, for some kinds of material, he of ordinary malleable iron,
or the like, but they are preferably of tool steel tempered to suit the kind of

page_text: work for which they are intended. Their axis may be in any position suitable to
the work required of the cutters, but preferably the axis is in a shank, which
can be rapidly placed and secured in a socket attached to a tool bar, the object
being to afford a means of quickly changing the tools, for instance when it is
required to substitute a set of moulding cutters for a set of dividing cutters, so
that immediately blocks of stone have been divided they can be moulded
without any waste of time. The axes of the cutters may
travel outside of the material being cut, when they may be mounted as
shewn in Figures 1, 2, 3, 10 and 11, or they may travel within it, by their
holders being let flush into stiff blades the one end of which is firmly attached
to the tool bar, the cutters carried by the other end of each blade, being so pro-
portioned or arranged as to give a width of cut sufficient for the entrance of the
blades as illustrated in Figures 4 to 9.
The cutters may be small or large in diameter, and they may be thick or
thin, and the teeth of the respective cutters may be situated at the same distances
from their centres, or at unequal distances in the different cutters, so as to cut
a moulding of any desired form when the cutters are run to and fro across a
stone and fed thereinto. The angles of the teeth may vary with their pitch
and depth, and with the diameter of each particular cutter, and with the par-
ticular purpose for which they are intended."
In the case of teeth intended to separate on the backward stroke as well as on
the forward stroke the portions of each tooth, on either side of a line drawn
from the point of the tooth, will be symmetrical; that is to say the angle on
each side of the centre line of each tooth will be the same: These angles may
differ in different cutters according to the degree of wedging effect desired.
When, however, action of the cutters on the stone is required only during the
stroke in one direction, one of the sides of each tooth may be angled so as to be
nor free from contact than the side of tooth used as a wedge. The cutters may
be formed by punching, pressing, stamping, or casting to required shape, or by
inilling, but for most purposes in stone cutting, thin sheets of steel punched cold
and grouped together will be found preferable on account of the rapidity with
which they can be made in a power press, and on account of the small amount
of steel required for a set of cutters of small diameter, such as are preferred for
most purposes, and because small cutters such as are illustrated in Figures 4 to 9.
and in Figure 11, can be readily and rapidly dressed by means of an ordinary
saw file, so that their efficiency can be maintained cheaply and readily and with-
out the aid of costly tools. With holders secured to the blades as illustrated, the
tools can be quickly removed and replaced, so that no time need be lost in
changing the cutters and, when the small cutters are worn out the quantity of
steel lost is inconsiderable. The small sized cutters attached to blades, as illus-
rated in Figures 4 to 9 are specially adapted for dividing deep blocks of stone,
and are also suitable, when properly placed, for producing plane surfaces on
blocks of stone. For dividing, the cutters may be in any desired number which
each blade will accommodate, they being carried one behind the other along the
lower edge of the blade, as, shewn in Figure 5, and every alternate cutter is
double, the journal being between the pair (as shewn in Figures 6 and 7) the
intervening cutters being single (as shewn in Figures 8 and 9) the holder taking
the strain on each side of the cutter. The double cutters act on the stone at
parts which are not touched by the single cutter, and the single cutters cut
what the double cutter does not touch, the object of the device being to clear the
way for the blades to which the cutter holders are secured. This is effected by
the double cutter, because its outer sides extend beyond the sides of blades, (as
seen in Figure 6) but the double cutters alone could not complete the work owing
to the space required for what may be termed the fulcrum, so that the single
cutters are required to cut away what the double cutters leave. To ensure a
complete clearance the outer edges of the single cutters should extend beyond the
inner edges of the double cutters, the outer sides of which are preferably slightly

page_text: concave so that the cutter edges are further out than the middle of the cutter
dises By this means cutters of very small diameter can be used for dividing
deep stone, and the like, though of course, cutters of any desired diameter can
be used. For dividing, cutters may be used of such a diameter that the fulcrum
will never enter the divided space, and in such cases one cutter (which may be a
thin one) may be used for each dividing ent, though if the dividing cut be very
deep, it will generally speaking, he found more economical to use the arrange-
ment of small cutters herein before described. In the case, however, of cutting
the edges of say, paving stones, thin cutters will be preferable. In that case, the
stones may be laid one above another with the edge of each stone back from
the edge of the one immediately under it, so that the projecting parts represent a
series of steps (see Figure 3) then by setting, by means of the screwed rods
and nuts c the blades at the proper distances apart to act on each stone, the
blades being of varying lengths to suit the positions of the several stones, the
whole of the edges can be cut simultaneously by the said cutters.
Pieces of wood e should be placed beneath the stones, as shewn, to support
them, and also to keep them at such a distance from each other, that the cutters
will not touch the stones which are below those which they have cut.
In moulding, the cutters run in journals on either side as illustrated in
Figure 10.
In producing plane surfaces on the outer sides of stone, the cutters may run
in rows similarly to the arrangements explained for dividing operations.
The aforesaid bars b, have threads running their whole length, so that by
adjusting the nuts c, the blades a, for carrying the dividing cutters, can be set,
and fixed, at any desired distance from each other. The arrangement is such.
that the blades can be spaced as required. and the sides of the blades be adiusted
vertically, and on a line with the intended line of cut, with great accuracy. There
are flanges secured to the blades, which have set pins for fixing them in the
adjusted position, and above there are adjustable bars e These arrangements
retain the blades firmly in the positions proper for each operation, the blades
being made sufficiently rigid to be free from flexure.
In the case of separating stone, as illustrated in Figure 3, where the cutters
enter the stone to an extent less than half their diameter, each cutter a*, is pre-
ferably a single disc of thin sheet steel. because thin sheet steel can be made
sufficiently rigid to perform the work required of cutters for such work, but where
stone is required to be divided for a considerable depth, it is preferable to use
cutters of small diameter, (as illustrated in Figures 4, 5, 6, 7. S. and 9) and of
such thickness (either by grouping thin dises or in single discs) as will allow
of the double cutters clearing the way for the blade, and allow the single cutter
to separate the part untouched by the double cutters. The thickness and shape
of the moulding cutters, (Figure 10) are determined by the span and shape of the
desired moulding, and may consist of a number of thin discs of different dia-
meters, or the said cutters may be each in one piece, while the diameters of the
moulding cutters, may be as small as will allow clearance for the cutter holder.
The latter remark applies also to cutters for producing plane surfaces on the face
of a block of stone, (as illustrated by Figure 11) but in that case the thickness of
each cutter, and the relative difference in the diameters of its component parts,
is dependent on the kind of work desired. In this case also the cutters may each
consist of a number of thin dises grouped together, or they may be in single
pieces.
When oven and smooth surfaces are desired, the pitch of teeth should be fine,
and the cutters should be finely fed to their work, while the speed at which the
cuiters can he actuated is limited only by the speed of the machine used to
work them, because the cutters when operating, according to my invention, will
not become unduly heated.
The advantages of the method of operation according to my invention, will be
clearly understood when it is considered that by lightly striking a suitable chisel,

page_text: pieces can be separated from the edges of a block of stone, and that by lightly
striking wedges, large blocks of sandstone can be split so that vast numbers of
particles can be separated with small effort in a very short time. And when it
is remembered that the latter easy and rapid hand operation (in a direction
similar to that of separation according to my invention) is separation en masse,
whilst I separate in detail, it becomes evident that the resistance, in operating
according to my invention, is extremely small. It is for that reason that the
cutters, according to my invention, when working at a very great speed, have
small liability to heat, and for the same reason, the power absorbed by the resist-
ance to separation is very small. But these hand worked methods of separation,
resemble separation according to my invention only, in respect to similarity in
the smallness of resistance, for in all other respects, the respective results are
entirely different. Besides bruising the edges of the stone, and often breaking it
in a different manner from that intended, the new surfaces obtained, by splitting
sandstone for example, are in all cases so irregular, that the stone has afterwards
to be dressed before it can be said to be finished, whereas according to my
invention, the act of separation also finishes the stone, giving it an even and
smooth surface, or an even and rough surface, as may be desired, while in no
case is there any liability to break any more of the stone, than the particles in
close proximity to each tooth at the moment of its action on the material.
As before stated, the cutters can be operated by any planing, boring, or
analogous machine, provided that when the cutters are in contact with the stone
to be operated upon, and the driving motion is applied, the said cutters will
rotate truly on their axes, and traverse in the directions desired.
The grit should be kept clear by the projection of water, or by any other
effective means. Stone, or other material as hereinbefore defined, can, according
to my invention, be bored, divided, dressed and moulded with great accuracy,
rapidity and economy.
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 claim is:
Means for cutting stone or the like, consisting of a cutter, or cutters, having
circular series of teeth, or wedges, and mounted so as to be free to rotate, and
provided with means for applying thereto a force to cause the said teeth, or
wedges, to enter the material, and a traversing movement, such that when the
apparatus is in operation, the said teeth or wedges successively enter the material
forward of each other and break off the successive portions in the rearward
direction, substantially as hereinbefore explained.
Tia 91st day of Tanambar 1900
JOHNSONS & WILLCOX.
47, Lincoln's Inn Fields, London, W.C., Agents.