IMPROVEMENTS IN BENDING TIMBER
Year: 1856

page_text: LETTERS PATENT to John Imray, of Bridge Road, Lambeth, in the
County of Surrey, Engineer, for the Invention of "IMPROVEMENTS IN
BENDING TIMBER."
Sealed the 24th December 1856, and dated the 22nd July 1856.
PROVISIONAL SPECIFICATION left by tho said John Imray at the Office
of the Commissioners of Patents, with his Petition, on the 22nd July
1856.
I, JOHN IMBAY, of Bridge Road, Lambeth, in the County of Surrey,
Engineer, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN BENDING TIMBEB," to be as follows:-
My Invention consists of apparatus for bending timber by means of hydraulic
pressure. A piece of timber prepared by steaming is laid with one face against
a convex mould, which bears against the ram of a bydraulic press. Along the
opposite face of the timber is stretched a flexible strap or chain, having at its
ends angle pieces, fitted with screws pressing against the ends of the timber,
and connected by links to the hydraulic cylinder. When the pressure is applied
the mould is pressed against the timber, which being retained at the ends is
caused to bend to the mould, the end screws being somewhat released to
permit a little elongation of the timber during the process; or a cylindrical
mould is mounted in bearings so as to be free to revolve round its axis. One

page_text: end of a piece of timber prepared by steaming is clamped firmly to the mould,
and the other end bears against the ram of a bydraulic press. The pressure
being applied, the timber is forced onwards, and causes the mould to revolve
and bend the timber round it, the outer curved surface being covered by a
flexible strap or chain, fixed at one end to the mould, and at the other to the
hydraulic ram, with an adjusting screw at either end, which may be released
to permit elongation of the timber during the process; or a cylindrical mould
is mounted on sliding bearings, connected by links to the ram of a hydraulic
press. One end of a piece of timber, prepared by steaming, is clamped firmly
to the surface of the mould, and the other end bears against the ram of a second
hydraulic press. A flexible strap or chain covers the outer surface of the
timber, being fixed to the mould at one end, and to the second hydraulic
cylinder at the other. When the pressure is applied in the first press the
mould is drawn along parallel to the length of the timber, and the timber
being retained at the end with such force as may be necessary by the second
press, the mould is caused to revolve or roll along the timber, and thus to
bend it.
When the timber is bent by any of these modes, side casings are fitted to
prevent its bulging laterally, and a tie rod is fastened to the ends of the bent
timber, so that it may be removed along with its tie and back strap, and left
to dry and set to its curved form.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Imray in the Great Seal Patent Office on the
15th January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOUN
IMRAY, of Bridge Road, Lambeth, in the County of Surrey, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of July, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Fler heirs and successors, give and grant unto me, the said
John Imray, Her special licence that I, the said John Imray, my executors,
administrators, and assigns, or such others as I, the said John Imray, my
executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and vend,

page_text: within the United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN BENDING TIMBER," upоп
the condition (amongst others) that I, the said John Imray, my executors or
administrators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Imray, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
DESCRIPTION OF THE DRAWING.
Figure 1 represents a longitudinal section, and Figure 2 an end elevation,
of my apparatus for bending a piece of timber near one end of its length;
Figure 3 represents a longitudinal section of the same apparatus when the
timber is bent; and Figure 4 represents a transverse section on the line
marked A, A, on Figure 3. a, a, the framing; b, a mould, consisting of two
sido frames an an arched piece c, with flanges fitting into recesses in the
sides; d, a shaft on which the mould is fitted; and e, e, two rollers on the
same shaft, guided within slots in the framing; f, a hydraulic press, fixed in
the framing; g, a cross head on the end of the ram; and h, h, side rods, con-
necting the cross head g with the ends of the shaft d; i, i, the timber; k, k, a
flexible strap covering one side of it, and fixed to angle pieces 1, 1, at each
end; m, m, casing enclosing the part of the timber which is not intended to
be bent, and secured by wedges n, n, driven between it and cross bars fitted in
the framing; o, cross bar and wedges retaining the one end of the timber;
p. p, a double chain, with bars q, q, extending across the timber, of which a
transverse section is represented in Figure 5, and a plan of part of which is
represented in Figure 6 to an increased scale. These bars q. q, are made to
press on the flexible strap k, k, and the links are arranged so that their centres
may occupy points in the curvature to which the flexible strap is bent. The
chains are fixed at one end to the casing m, and at the other to a piece r,
which is secured to a boss, projecting from the mould 6 by means of a key,
which also compresses the end of the timber inserted with the flexible strap
and angle plate into the hollow part of the boss. 8, 8, are arched covers,
secured against the sides of the timber by wedges t, t, driven between them
and the projecting sides of the mould.

page_text: The timber being placed in the apparatus, as represented in Figure 1, with
its back strap, and the chains and cross bars, casing and side covers keyed
in their places, water is forced into the bydraulic press, and the ram and
cross head are caused to move longitudinally, drawing by means of the side
rods h, h, the shaft d, which is controlled by the rollers e, e, so as to move
rectilineally; the mould 6 being free to revolve round the axis d, and the
timber being prevented from sliding longitudinally, and being fixed to the
circumference of the mould, is bent by the rolling of the mould along its under
surface, as indicated in Figure 3. When the flexure is completed, a bolt u
is passed through holes in the angle pieces 2, 1, and tightened by nuts or keys;
the other keys and wedges are slacked and the casing and chain removed, and
the timber is withdrawn from the apparatus along with the back strap k, k,
and tie bolt u, which retain it in its bent condition till it becomes set.
Figure 7 represents a longitudinal, and Figure 8 a transverse section, of
my apparatus for bending a piece of timber near the middle of its length;
and Figure 9 represents an elevation of the same apparatus when the timber
is bent. a, a, the timber prepared by steaming; b, b, a flexible strap, covering
one side of the timber, fixed at each end to angle pieces c, c, which are pierced
with holes for bolts; d, d, a flat chain, fixed at each end to bosses e, e, pierced
with bolt holes; h, a bydraulic press; 1, 1, bolts passing through lugs on a
ring fitted to the bottom of the hydraulic press; f, f, tie rods, connecting the
bolts 1, 1, with bolts passing through the bosses e, e, and having excentric
bosses at e, e, on which are fitted tie rods g, g, connecting them with bolts
passing through the angle pieces c, c; k, a mould, consisting of two sides
and an arched piece m, with flanges fitting into recesses in the sides; n, n,
arched pieces for covering the sides of the timber, secured by wedges o driven
between them and flanges projecting from the sides of the mould k. On
water being forced into the hydraulic press, the ram and mould are forced
against the timber, and the ends e, e, of the chain being retained by the tio
rods f, f, the timber is bent into an arch, while, by the revolution of the tie
rods g, g, during the flexure round the excentric bosses at e, e, the distances
between the centres of the bolts passing through c, c, and e, e, respectively are
increased, to allow for the bending of the chain d, d, round a curve of larger
radius than that of the back strap b, b. Instead of an ordinary flat chain d, d,
I sometimes use a double chain with cross bars, like that already described,
and represented in Figures 5 and 6, and in this case the excentric bosses at
e, e, are not required. When the flexure is completed, a bolt p is passed
through holes in the angle pieces c, c, and tightened by nuts or keys at each
end. The tie rods f, f, g, 9, and the chain d, d, are then disconnected, and

page_text: the wedges o, o, being loosened and side covers n, n, removed, the timber is
withdrawn from the apparatus along with the back strap b, b, and tie bolt p,
which retain it in its bent condition until it becomes set.
I do not claim as my Invention the preparation of timber for bending by
steaming or other processes, nor do I claim the application of a flat chain or
flexible strap or side casings to timber undergoing flexure, or of strap and
tie rods to retain it in its bent condition; but I do claim the application of
bydraulic pressure in conjunction with casings, flexible strap and chain, to the
bending of timber, by causing a curved mould, mounted on an axis and
attached to one end of a fixed piece of timber, to bend the timber upon its
circumference, or by forcing a curved mould against the timber while the
timber is retained by tie rods at points towards each end.
In witness whereof, I, the said John Imray, have hereunto set my hand
and seal, this Fifteenth day of January, in the year of our Lord Ono
thousand eight hundred and fifty-seven.
Witness,
S. CARPMAEL.
JOHN IMRAY. (L.S.)