AN IMPROVEMENT IN MACHINERY FOR DRESSING THE SURFACES OF STONE
Year: 1876

page_text: LETTERS PATENT to Francis Brown, of Cathcart, in the County of Renfrew,
North Britain, Quarry Master, for the Invention of "AN IMPROVEMENT IN
MACHINERY FOR DRESSING THE SURFACES OF STONE."
Scaled the 7th October 1876, and dated the 20th May 1876.
PROVISIONAL SPECIFICATION left by the said Francis Brown at the Office
of the Commissioners of l'atents on the 20th May 1876.
FRANCIS BROWN, of Cathcart, in the County of Renfrew, North Britain, Quarry
Master. "AN IMPROVEMENT IN MACHINERY FOR DRESSING THE SURFACES OF
STONE."
This Invention, which relates to an improvement in machinery for dressing the
Burfaces of stone, has for its object to produce level or flat surfaces on the blocks
of stones used in ashlar or analogous masonry.
The Invention consists essentially in an improved arrangement of rotating body
and disposition of the cutters in the same. The rotating body consists of a cylinder
on whose surface rows of brackets project, provided with holes in which the tools
are carried. The tools consist of short pieces of bar steel, whose edges or cutting
portions are ground straight, so that when several tools are placed together on the
cylinder they form a straight row throughout with spaces or divisions between
cach tool. These spaces or divisions would when the tools are entting cause ridges
to be left projecting up between the parts cut by cach tool, and to obviate this
the tools in alternate rows are so set that the ridges which are left between the
tools in any one row are cut off by the tools in a succeeding row, that is to say,
the tools in one row are set opposite the spaces between the tools in another row.
The cylinder and tools rotate over the surface of the stone or stones to be dressed,
which are traversed beneath them on a table.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Francis Brown in the Great Seal Patent Office on the 17th November
1876.
FRANCIS BROWN, of Cathcart, in the County of Renfrew, North Britain, Quarry
Master. "AN IMPROVEMENT IN MACHINERY FOR DRESSING THE SURFACES OF
STONE."
My said Invention, which relates to an improvement in machinery for dressing
the surfaces of stone, has for its object to produce level or flat surfaces on the blocks
of stone used in ashlar or analogous masonry.
And the Invention consists essentially in an improved arrangement of rotating
body or cylinder, and disposition of the cutters in the same, and shown in two
forms or constructions in side elevation and transverse section in Figures 1, 2, and
3, 4, respectively, to a large scale as detached from the stone-cutting machine,
which is shown complete to a small scale in side and end elevation and plan
respectively in Figures 5, 6, and 7, the same reference letters and numerals indi-
cating the same or like parts in all the Figures where shown.
This rotating body consists of a cylinder or barrel A, preferably made in two halves
bolted together at their ends A", as shown in Figures 1, 2, and 6, on whose surface rows
of brackets or longitudinal ridges A' project, provided with corresponding rows of deep
holes Bin or through then, and in which the cutting tools C are carried and secured.
The tools C (which are shown in edge and side views to a large scale detached in
Figures 1 A and 2 A, and as secured in the cylinder in Figures 1 and 2), consist
of short pieces of broad thin bar steel, whose end edges or curved cutting parts CT
are hammered sharp and broadened out and tempered at the cutting points, so that
when a number or set of tools C are placed together in their holes B in the cylinder
A they form a nearly straight row or rows throughout, with spaces or divisions
between each tool C, as seen particularly in Figure 1. The spaces or divisions
would, when the tools C are cutting, cause ridges to be left projecting up on the
stone between the parts cut by each tool, and to obviate this the holes B and
tools C in the alternate rows are so set that the ridges which are left between:
the tools of any one row are cut off by the tools C in the succeeding row, that is to
say, the tools in one row are set opposite the spaces between the tools in the
adjacent rows. The cylinder A rotates with the driving shaft 1, on which it is
keyed, with the tools C in it as described, immediately over the surface of the stone
or stones to be dressed, shown in dotted lines in Figures 5 and 6, and which are:
traversed towards them on the travelling table of the machine below them, as
indicated in the general arrangement of the stone dressing machine, Figures 5, 6,
and 7 for actuating these cylinders and cutters and traversing the stones.
Figures 1 and 2, and 5, 6, and 7, the cylinder A is shown with its tool holes B
formed in rows parallel to the axis, and therefore having its joint a, a, dividing
it in two halves in a flat plane through its axis between the ridges A¹ and holes B,
and bolted together by screw bolts passed through strong lugs at their ends A",
where they are also bored some distance in to tightly fit the shaft 1, to which it is
further secured by one or more keys or feathers at each end. The outer surface
of the cylinder or snugs A', containing the recesses or mortices B for the tools, is
preferably turned cylindrically, and the tools when inserted into their recesses are set
by a seginental template laid on the turned part to a uniform radial distance from
the centre at the cutting part C where they are each fixed by a steel pinching screw c,
all as seen particularly in Figure 2.
In
A second modification of this cylinder A is shown in Figures 3 and 4, in which
the parallel rows of tool holes and snugs are set spirally round the circumference
instead of parallel to the axis, as in the former modification, and the separating
joint a , dividing the two halves of the cylinder is consequently in this case
made to follow the same curvilinear plane through the solid metal between the
spiral rows of snugs and recesses A¹, B, for the tools, so that the snugs and bolts
securing them at their ends A¹¹ cross each other, as seen particularly in Figure 4,

page_text: otherwise this modification and the mode of fixing the tools are substantially the
same as that shown in Figures 1 and 2, except that in cutting the rows of tools C
do not all cut at once but steadily and gradually, beginning with the advanced end
of each spiral row and ending with the rear or backward end, just as the advanced
cutters of the succeeding row begin to cut, thus giving a steadier action suitable for
some classes of work. Although these cutting cylinders A have been described as
preferably made in two halves and bolted together at the joint a. a, it is to be
understood that they might be cast solid or in one piece with or without shrunk
malleable iron rings at their ends, where they are keyed or otherwise secured to
their driving shafts 1.
Instead of making each tool or cutter C, C¹, in one piece of steel, or of iron with
steel or casehardened cutting points C', as shown in Figures 1 and 2, and 1 A and
2 A, a strong bent or kneed steel or iron tool holder D, D', may be used, as shown
in side elevation and edge view or plan in Figures 1 B and 2 B, detached to a
large scale formed in two halves as a body D and cover D¹, jointed up the centre
at d, d; the kneed parts nt d', ', being formed broader and with a recess either
in the lower or upper part D, D¹, to receive and act as a griper of the actual
cutting tool D* made or cut out of a piece of thin parallel, rolled, or hammered
steel, or it might be caschardened iron, and held fast in the groove between the
joints d, d, by the griping action of the pinching screws c when the stem parts
at d, d, are inserted in the recesses B in the cylinder A, which they are made to
fit like the stems C of the cutters shown in the former Figures. When the cutters
or pieces of steel D* wear away at the point the pinching screws c are slackened,
and the cutters drawn out three-eighths of an inch or so to a proper cutting distance,
as shown in Figures 1 Band 2 B, and fixed again in their holes B in the cylinder A
by tightening up the pinching screws in the entire set of holes in the cylinder
ready for a re-commencement of the cutting action of the machine and tools.
Referring to the modification or general construction and arrangement of the
machine shown in Figures 5, 6, and 7, for producing flat surfaces on stones with
these new or improved cylinders and cutters, this consists of two main strong
side standards 2 bolted by broad flanges or sole plates at their base to a suitable
foundation of beams 2¹ and masonry, and at the upper part to each other by
transverse stays at 211, all so as to carry the shaft 1 of the cutting cylinder and
tools A, B, C, by its journals 1¹ in bearing bushes 3, bolted together vertically,
and with guiding and griping flanges at 3¹ so as to slide or rise and fall in the
lower part of a long guiding or sliding recess 2111 formed or planed in the centre
of each of the two side frames 2. The upper part of these recesses are fitted
with corresponding bushes 44, 51, carrying the intermediate and prime moving
shafts 4 and 5, all bolted or secured together by the strong central bars or
bolts 4, 5, at suitable distances apart to keep their first and second motion
wheels 6, 6, and 7, 71, in proper working gear, and so as to be all raised and
lowered parallely and simultaneously by the screws 8 attached at their lower
ends to the bushes 5¹ of the driving shaft 5. These screws pass through deep
nuts in the bevel wheels 81 at the upper part of the fraunes 2, actuated by the
pinions 8 gearing into them, keyed on the outer ends of the spindle 9 carried in
bearing brackets 91 secured to the upper part of the frame 2, the spindle or shaft 9)
being actuated by the cross hand lovers or wheel 10 in the centre, turned by an
attendant on a platform at the upper part of the frame, not shown in the Drawings,
so as to raise or lower the cutting cylinder or drumn A (and its actuating gearing)
to the proper height for the stones secured on a portable plate 12 on the carrying
or traversing table or carriage 13, carried on wheels 14, running on rails 15, secured
by chairs to the same foundation 21 as the side frames 2. The first motion shaft 5
is driven at a high speed through the fast an loose pulleys 11 mounted on its
one end, and by a belt 111, indicated in dotted lines in Figure 5, passed over them
from a pulley on the prime motive or engine shaft for the purpose, and at such an
angle that the raising and lowering of the shaft 5 does not materially affect the
tightening or slackening of the driving belt; or when this cannot be avoided the

page_text: belt can be raised or depressed to a uniform tightness by a pulley for the purpose
carried on a weighted shifting lever or spindle, having a fly wheel 11" mounted on
the other end of the shaft 5 so as to give a steady motion to the whole of the shafts
and gearing and new cutting barrel A, all as indicated by the arrows on the several
parts, and started and stopped at pleasure by the usual belt shifting fork bar or
lever fitted near the pulleys 11, though these are not shown in the Drawings. The
slow forward automatic feeding motion is given to the traversing table or carriage 13
(carrying the stones to be dressed in the direction indicated by the arrows on it
in Figures 5 and 7) through the long deep rack 10 bolted to its under side near the
middle, with teeth on its lower surface gearing into the spur pinion 16' keyed on
the inner end of the transverse horizontal shaft 17, carried in bearing blocks 17',
secured to the sides of the foundation beams 2¹, and in a plummer block 1711 secured
to the beam or sole plate 2* at its outer end beyond its loose actuating screw
wheel 18 and shifting clutch 19 both mounted on it, so that the latter takes into
a corresponding coupling box 19' formed on the outer face of the wheel 18 so as
then to be driven automatically in the direction of the arrows on it, and the table 13
by its actuating screw 181 carried to revolve by its hollow end journals in the
strong bearing bracket 20, screwed by a broad deep flange to the side of the
foundation beam or masonry 21, and form the steadying bearing for the lower end
of the vertical shaft 21, which is fitted with a groove and feather to slide through
the deep eye of the screw 18¹ to actuate it while the shaft 21 is being carried by
the bearing bracket 21' at its top end, secured to one of the sliding bushes 3 of the
shaft 1 which actuates it direct through the bevel wheel and pinion 22, 22¹, respec-
tively keyed on their adjacent ends. As the table or carriage 13 and stones are
thus fed in against or in the opposite direction to the revolving barrel or cutters
A, B, C, a set of differential holding or retaining pawls 23 are fitted to oscillate in
bearings on the back end of the carriage 13 with their lower free ends falling and
taking into the holding notches of a strong fixed or retaining ratchet rack 24,
secured to a beam or other equivalent 24¹ of the foundation below the traversing
rack 16 at the front part of the machine. This ratchet rack 24 and its pawls 23
make good and retain each increment of a quarter of an inch or less of the forward
motion of the table 13, and take nearly all the strain of the cutting action of the
stone off the feeding wheels and gearing 16, 161, 18, 18¹, and 22, 22, thus giving a
much steadier feed motion to the stones and cutting motion of the barrel A, B, C,
and its driving gear. When the table 13 has been fed forward as described until
the stones on it have passed under the cutting barrel, and have their upper surfaco
dressed, the weighted lever 25 and lowest pawl 23 on which it is keyed are tilted
so as to lift the whole out of their rack 24, when the coupling 19 is drawn back
out of the coupling 19' of the screw wheel 18 so as to have the table brought quickly
back by hand through the spoke arms or wheel 26, keyed on the outer end of the
shaft 17 all ready for lifting away the portable table or plate 12 with the dressed
stones on it by a steam jib, crane, or other equivalent, and proper chain or link
slings hooked on to the ears 12¹ at the sides of the plate 12, and replace another
plate 12 (with fresh stones secured on it) on to the carriage 13 ready for being
dressed on their upper surface by again inserting the clutch 19 into the box 19¹ of
the wheel 18 and letting down the pawls 23 so as to automatically feed forward
the table, all as herein-before described, without the necessity of stopping the
motion of the cutting barrel or machine, unless when the cutters have to be
adjusted or a fresh barrel of cutters fixed in the shaft 1, which may be done in the
morning or evening or at a meal hour or while the machine is stopped for that
purpose during the day. To keep the machine properly supplied with stones, three
or four duplicate portable plates 12 are required, set on a level bed or frame within
the range of the crane which moves over and lifts the plates with the stones z
secured on them. Each plate 12 is preferably planed flat, and is formed with rows
of holes 12 closely set all over, as also the top of the travelling carriage 13 to
which the former is fixed, so that the stones z are first levelled up on the sparo
plates upon the platform (while the machine is dressing other stones) by pieces of

page_text: 2
wood and wedges below them, and secured by cross bars and bolts or pieces of iron
inserted into the holes at the sides and ends, and with blocks here and there
between the stones to steady them, so that each plate 12 with the stones fixed on
it may be lifted on to and fixed to the carriage 13 (as the finished stones are lifted
off) to have their upper surface cut and dressed nearly flat by the revolving barrel
and cutters A, B, C, all as before described, and so on in succession. When the
stones are to be dressed parallel or to an equal thickness, the first dressed side of
the stones are laid down on the level plate 12 and secured as in the first instance
by spikes in the holes at the ends and sides or blocks at the ends or between the
stones, and when the edges are to be dressed in addition to one or both sides.
This is done by fixing the stones on the plates 12 with the dressed sides plumb,
either face to face or not as desired, with blocks and wedges below them and with
bolts or other irons in the holes at the ends and sides. When the surfaces of the
stones have to be polished after being so cut and dressed, the stones are preferably
lifted by the same crane or another one and placed and secured in the reciprocating
frames of a polishing machine so as to rub the dressed surfaces of two stones set
face to face with water and fine sand fed in between them until they are sufficiently
smoothed or polished, when they are removed ready for building purposes. One
such dressing machine, as that shown in Figures 5, 6, and 7, is at present found
capable of keeping two polishing machines constantly supplied with stones.
Having thus described the nature of my said Invention and the manner in which
the same is or may be performed, I have to state that I do not restrict myself to
the precise details herein described or delineated, but what I consider novel and
original and therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent is-
First. The general construction and arrangement of machinery for cutting or
dressing the surfaces of stones, all substantially as herein described in reference to
and shown in the accompanying Drawings or any mere modification thereof.
Second. The construction of cylinders or barrels A with alternating parallel rows
of holes B and cutters C for cutting or dressing the surfaces of stones, all substantially
as herein described in reference to and shown in the accompanying Drawings or any
inere modification thereof.
In witness whereof, I, the said Francis Brown, have hereunto set my hand and
seal, this Fifteenth day of November, in the year of our Lord One thousand
eight hundred and seventy-six
Witness,
W. R. M. THOMSON,
Patent Agent,
Glasgow.
FRANCIS BROWN. (L.S.)