AN IMPROVED MODE OF CUTTING THAT KIND OF SLATES COMMONLY CALLED ROOFING SLATES, THOUGH SOMETIMES USED FOR OTHER PURPOSES
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
PARKER BIDDER, of Great George Street, in the City of Westminster, Civil.
Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-sixth day of January, in the sixth year of Her reign, did,,
for Herself, Her heirs and successors, give and grant unto me, the said George
Parker Bidder, Her especial licence, full power, sole privilege and authority,
that I, the said George Parker Bidder, my exors, admiors, and assigns, or
such others as I, the said George Parker Bidder, my exors, adñiors, or assigns,
should at any time agree with, and no others, from time to time and at all
times during the term of years therein expressed, should and lawfully might
make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, my Invention of "AN IMPROVED MODE OF CUTTING THAT
KIND OF SLATES COMMONLY CALLED ROOFING SLATES, THOUGH SOMETIMES USED FOR
OTHER PURPOSES;" in which said Letters Patent is contained a proviso that I, the
said George Parker Bidder, shall cause a particular description of the nature
of my said Invention, and in what manner the same is to be performed, to.
be enrolled in Her said Majesty's High Court of Chancery within six, calendar.
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more.
fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the-said proviso, I, the said
George Parker Bidder, do hereby declare the nature of my Invention to
consist in cutting the edges of that kind of slates commonly called roofing
slates more rapidly and in a more perfect and uniform manner than that
heretofore practised, namely, by means of circular saws or cutters constantly
wet with water, and revolving at a high velocity, and represented in the Draw-
ings annexed as done in such manner that each pair of parallel edges is cut at
one operation, whereby I am enabled to produce such slates as are used for
roofing and other purposes at a lower cost and of a more perfect form than
those shaped by hand, according to the present mode of cutting that kind of slates,
videlicit, by chopping the slate against a straight edge, when large portions
of it are apt to split off, thus compelling the workman to reduce the size of the
slate to one of inferior value, whilst the edges are not so sharp or uniform as
by my method of cutting them. And, in further compliance with the said pro-
viso, I, the said George Parker Bidder, do hereby describe the manner in which
my said Invention is to be performed by the following statement thereof,
reference being had to the Drawings annexed, and to the figures and letters
marked thereon, similar letters being used to denote similar parts in all the
Ticures that is to co

page_text: the bases of which are supposed to be screwed to a foundation plate or fixed in
the ground, as the case may be; upon this frame are screwed two ribs or
bearers C, C, their upper edges being V-shaped, and grooves of a corres-
ponding shape are cast upon the under side of the frame or table D to guide it
while advancing; F is the saw shaft revolving in the bearings E, E¹; upon this
shaft are two circular saws G, G', which are fixed to it by means of two nuts
H, H; I, I, are two troughs screwed to the ribs C, C', which are supplied by
the pipes m, m, with water for the cutters to revolve in, the use of which
greatly facilitates the operation of cutting the slates; J, J, are loose collars
placed upon the shaft F to regulate the distance between tho cutters, and they
are screwed up to that cutter (which I call the shifting cutter) G¹, by the nut
II, turning upon a screw on the shaft F; L is a pulley fixed at the end of the
shaft F, which is worked by a strap from any first moving power, and which
communicates motion to the cutters G, G¹.
The table D, it will be seen in the Plan, Figure 2, Sheet 2, is provided with
holes to receive pegs M, M, against which the rough edges of the piece of
slate are placed during the operation of cutting the two first parallel edges, and
I have placed the holes close to each other that the pegs may be readily fixed
therein, to accommodate themselves to the unequal edges of the slate as
brought from the splitter's hands; N represents the said piece of slate placed
upon the table, and the cutters are also represented as having performed a
part of the first operation; the weighted rollers O, O, rest upon the slate to
keep it steady whilst being cut; these rollers are placed as near the saws as
possible, and are fixed upon a spindle P, turning freely in the guides Q, Q,
baving slots to allow the rollers to adjust themselves to the unequal surfaces of
the slate; R is a strong wrought-iron bar to which the guides Q, Q, are
attached, fixed to a wall at S, and also supported by a pillar T upon the
board W; Y is a band attached to the under side of the table D, one end of
which passes over a pulley a, upon a spindle turning in bushes in the side ribs
C, C; d is a water bucket suspended at the end of the band Y by means of a sling
b; c is a pin passing through the bucket d and sling b, upon which pin the bucket
turns; the ends of the pin c project on either side of the bucket, and slide in
grooves e, e, in the sides of the well f, f, in order to keep the bucket steady
during its ascent and descent; g is a catch lever having its fulcrum upon the
sling at h, and a notch which drops upon a stud i, fixed to the side of the
bucket, by which it is retained in the position shewn in the Drawing; the pin
c is situated below, and a little to one side of the centre of gravity of the
bucket when filled with water, so that when the catch lever g is raised tho

page_text: bucket is free to turn upon the-pin, and the centre of gravity being situated as
above described, out of the line of support, the bucket turns over in the
position shewn by the dotted figure beneath, and discharges the water con-
tained in it; and the water being so discharged, the centre of gravity of the
bucket is altered, and the weight 6, fixed to its bottom, brings it back to its
original position; the tail of the catch lever coming in contact with a stud a
upon the sling prevents the lever from falling while the bucket is discharging
the water. The other end of the band Y passes over a pulley y, similar in all
respects to the pulley a, and has attached to it a counterbalance weight, which
is sufficient to draw back the table after the water has been discharged from the
bucket d; the weight is suspended in a well 1; the weight is capable of being
adjusted to suit the different sizes of tables employed; is a water pipe which
is kept always charged; the branch is for supplying water to the bucket d, and
the branches m, m, supply the water troughs I, 1, in which the saws revolve;
n is a cock which is opened and shut by the lever handles o, o, which are
connected together by a rod p; q is a hose attached to the nozzle of the cock
n, through which water is supplied to the bucket; r, r, is a shaft turning in
bearings fixed to the floor, having upon it two treadles s, s', for emptying the
water bucket. This is done in the following manner :-To one end of the lever
of the treadle s is a rod u, which descends into the well, and has an adjustable
stop v upon it; by depressing either treadle, the stop comes against the end of
the catch lever g, and lifts it off the stud i, when the bucket being liberated
turns over and discharges the water into the well, and returns to the vertical
position as before described; wis a drain pipe to convey the water from the
well. The bucket being thus relieved of its weight, the counterbalance weight
z at the other end of the machine will draw the table back again ready to
receive another slate, and with it the bucket to be again filled with water;
W, W, are boards placed on each side the machine, a little lower than the level
of the table, to receive the rough pieces of slate after the cutting has taken place;
these boards are fixed to brackets V, V, which are screwed to the frame. In
order to cut the second pair of parallel edges of the slate after it has passed
through the machine as before described, it is necessary to remove the table D,
and place another in its stead, such as is represented at K, in Figures 4 and 5;
it is also necessary to shift one of the cutters to the required width, and at the
same time move inwards the rib C, to carry the narrow table; this is done
by removing the caps of the plummer blocks, and also the shaft F, with the
cutters; the nuts H, H', must then be unscrewed, and the cutters and loose
collars be taken off the shaft; the cutter G¹ be replaced upon the shaft between

page_text: two of the loose collars at the position Z, shown by dotted lines in Figures 2
and 3, (the collars being so arranged as to allow of its being placed at the
required distance from the cutter G,) the remaining collars are then to be put
on the shaft, and the nuts H, H', be screwed up again. The next operation is
to shift the rib or bearer C¹ to the proper width, this is done by loosening the
set screws 2, 2, and sliding the rib in the groove of the frame A, as far as
necessary, when the set screws are to be tightened up, and the table K. placed
thereon; the pulleys a and y with their shafts being taken out of their bearings
and replaced by others similar to that shewn at a', Figure 6. The shaft F
with its cutters is now to be placed again in its bearings and screwed up. It is
not necessary to have holes in the table K to receive the pegs which hold the
partially cut slate, as the edges on two sides being already cut parallel and
smooth will, when placed thercon, fit close to the proper guage, for which
purpose I have provided projections on lugs X, X, see Fig. 4, upon the edge
of the table, against which one of the cut edges of the slate is to be placed; it
will then be in a position to have the other two parallel sides cut. The band
is attached to the under side of the table K, as before described for the table D.
The water troughs being screwed to the ribs C, C', will, of course, be moved
with them, and in a proper position for the altered distance between the
cutters.
The operations of the machine are as follows:-The rough piece of slate
being adjusted to the pegs of the table, as shewn in the Drawings, and the
cutters being set in motion, cither of the lever handles o, o, must be turned into
the position shown by dotted lines; this will open the cock n, and fill the bucket
d with water; which will descend and draw the table and with it the slate
towards the cutters; and as soon as it passed the cutters and arrived at the stop
No. 4, the bucket will have reached the adjustable stop v, when the water
must be shut off by turning the lever handle o in the opposite direction; the
slate is then removed from, the table, and when the workman is ready, either of the
treadless, s', being depressed, will lift the rod u, and the stop v striking against
and lifting the catch lever g off the stud of the buckett d, it will immediately
overturn and empty itself of the water; the counterbalance weight will then
draw back the table against stops 5 at the end of the machine, ready to receive
another piece of slate to be cut, and in this way the operation is repeated.
Now, whereas I am aware that circular saws have heretofore been used for
cutting or shaping blocks or slabs of slate, and also thick pieces of slate - called
imperials, which have, I believe, occasionally, though very seldom, been used for
fancy roofing; but such saws, when used for that purpose, have been made to

page_text: revolve-at only low velocities, and have only been applied to cut one side at a
time, while the blocks or slabs of slate so cut as aforesaid have not been used
for those purposes to which the thin slates ordinarily called roofing slates are
applicable.
But whereas, if such thin slates as are commonly called roofing slates were
cut by circular saws, running at such low velocities as have heretofore been
used for cutting thicker pieces of slate, the process would be too long, and, con-
sequently, too expensive to be of any advantage, while, if the circular saws, as
ordinarily arranged for cutting thick pieces of slate, were merely applied to
cutting such thin slates as aforesaid by increasing their velocity, their temper
would at once be destroyed, and the operation could not be continued, while
the fine dust arising therefrom would create such an atmosphere as no work-
man could live in.
I therefore claim as my Invention, the cutting or shaping of that description of
thin slate, commonly known and used as roofing slates (be they applied to what
purpose they may), by means of circular saws or cutters, arranged to cut more
than one side of the slate at a time, and revolving in water, or constantly wet
with water, and at much greater velocities than have been heretofore used for
circular saws applied to the cutting of slate; in fact, at the greatest velocity
compatible with the facilities of the machine for feeding the said saws, and
consistently with a due reduction of expence, that which I have found convenient
being not less that 1,200 feet per minute.
I also claim the machine herein-before described, though I do not confine
myself to the precise manner of moving the tables or frames to and fro, as other
means may be found to answer as well; and such my Invention being, to the
best of my knowledge and belief, entirely new, and never before used within
that part of Her said Majesty's United Kingdom of Great Britain and Ireland
called England, Her said Dominion of Wales, or Town of Berwick-upon-Tweed,
I do hereby declare this to be my Specification of the same; and that I do
verily believe this my said Specification doth comply in all respects, fully and
without reserve or disguise, with the proviso in the said herein-before in part
recited Letters Patent contained. Wherefore I do hereby claim to maintain
exclusive right and privilege to my said Invention.
In witness whereof, I, the said George Parker Bidder, have hereunto set
my hand and seal, this Twenty-sixth day of July, in the year of our
Lord One thousand eight bundred and forty-three.
GEORGE PARKER (L.s.) BIDDER.

page_text: AND BE IT REMEMBERED, that on the Twenty-sixth day of July, in
the year of our Lord 1843, the aforesaid George Parker Bidder, Esquire, came
before our said Lady the Queen in Her Chancery, and acknowledged the Spe-
cification aforesaid, and all and every thing therein contained and specified, in
form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Enrolled the Twenty-sixth day of July, in the year of our Lord One
thousand eight hundred and forty-three.