IMPROVEMENTS IN THE CONSTRUCTION OF ANNEALING OVENS AND KILNS
Year: 1869

page_text: LETTERS PATENT to John Tenwick, of Grantham, in the County of
Lincoln, Moulder, for the Invention of "IMPROVEMENTS IN THE
CONSTRUCTION OF ANNEALING OVENS AND KILNS."
Sealed the 10th September 1869, and dated the 13th March 1869.
PROVISIONAL SPECIFICATION left by the said John Tenwick at the
Office of the Commissioners of Patents, with his Petition, on the
13th March 1869.
I, JOHN TENWICK, of Grantham, in the County of Lincoln, Moulder,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE CONSTRUCTION OF ANNEALING OVENS AND KILNS," to be as follows:-
This Invention has for its object improvements in the construction of
annealing ovens and kilns, whereby a considerable saving in fuel-is
effected, greater ease in working is obtained, the packing being all out-
side instead of inside the oven, and any article can be withdrawn and
the oven recharged without reducing the fires or in any way affecting
the other work, one man being able to control an oven capable of
holding twenty tons.
In carrying my Invention into effect I build the ovens or kilns of the
required size and of a circular form, the outer casing being made of iron,

page_text: steel, or other hard metal lined inside with fire-brick or other suitable
fireproof material; and provided with the necessary fire-bai's, ash-pits,
dampers, and other mechanism and devices ordinarily required in
annealing ovens and kilns. By preference I use two fires, one on either
side of the oven or kiln, which fires are provided with flues forming an
ascending and descending fluc which may be used together or separately,
or one may be opened and the other closed by means of a double
damper, so that the flame and heat can be made to pass from right to
left, and vice versa, through the oven or kiln as desired. Inside the
oven or kiln, turning on a centre pivot and mounted in suitable bearings
on rollers or wheels, is a revolving fireproof floor or turntable having
rails radiating from its centre which serve to guide the front wheels
of the carriages or trucks, two other rails run parallel with each of
these radiating rails for guiding the carriages or trucks into their proper
positions in the oven or kiln after having been packed from the outside.
These carriages or trucks are of a segmental form, and are provided with
wheels or rollers for running them into and out of the oven or .kiln,
friction rollers are also placed at the back of the trucks to prevent the
said trucks from rubbing against the brick sides as the turntable or floor
revolves. These trucks are formed of iron, steel, or other suitable metal
about 5 inches in depth, which is filled with sand, over which about
12 inches of fire-bricks are placed. Through the outer casing of steel
and the lining of fire-bricks I form a circular or other shaped opening.
for watching the progress of the work, and also for admitting air, into
the oven or kiln; the door of this opening or spy hole is set on an
inclined plane and requires no fastening, and is easily opened and closed.
The under side of the revolving floor or turntable is made to gear with a
wheel fixed to a shaft in connection with a set of wheel work turned
by a hand wheel or other means, and as the wheel is turned from right:
to left the turntable or floor is made to revolve and any particular
carriage or truck can be immediately withdrawn when it comes opposite,
the door, and a fresh one can be immediately inserted. The oven or
kiln door is raised and lowered by means of a screw gearing with
a set of wheels, or by any other suitable means, and when closed
the door is kept tight home by means of an eccentric shaft pressing
against it.

page_text: SPECIFICATION in pursuance of 'the conditions of the Letters Patent,
filed by the said John Tenwick in the Great Seal Patent Office on
the 11th September 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, JOIN
TENWICK, of Grantham, in the County of Lincoln, Moulder, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of March, in the year
of our Lord One thousand cight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Tenwick, Her special licence
that I, the said John Tenwick, my executors, administrators, and
assigns, or such others as I, the said John Tenwick, 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, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN THE CONSTRUCTION OF ANNEALING OVENS AND KILNS," upon the condition
(amongst others) that. I, the said John Tenwick, 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 Tenwick, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement, that is to say :-
;
This Invention has for its object improvements in the construction
of annealing ovens and kilns, by means of which a considerable economy
in fuel is realized, and a greater facility in the working is obtained than
in annealing ovens or kilns as now constructed. In working the ovens
or kilus now generally in use the articles required to be annealed are
packed in the ovens at the same time, and none of them are removed
till the fire is put out, and as some articles do not require the same

page_text: amount of fire as others, some are frequently in the oven too long and
some too short a time. The oven I construct, as herein described, enables
some of the articles to be taken out and the oven recharged without
extinguishing or reducing the fires, and without interfering with tho
other articles in the oven. All the packing is done outside the oven,
and the expence of labor in the management of the oven is very
considerably reduced.
In carrying out my Invention I construct the ovens and kilns of any
required size and of a circular form inside. The outside covering is made
of iron or steel, or any other metal suitable for the purpose, lined with
fire-bricks, or other convenient material which can resist the fire, and I
provide fire-bars, ash pans, regulators, or dampers, and other accessories
of the kind now in use in the construction of annealing ovens. I prefer
using two fires one on each side of the oven or kiln, and I prefer having
flues both ascending and descending, which can be used together or
separately, or one may be open and the other shut by means of a double
regulator or damper, so that the flame and heat can be made to pass
through the oven from the right to the left, or vice versa, as may be
required. This arrangement I find convenient to assist in consuming
the smoke and utilising the heat. In tho inside of the oven I place a
turntable turning on a centre pivot, and moving on rollers or wheels
placed in a proper position, and having upon it rails which radiato from
its centre, and which serve to guide the wheel in the front of the
,carriages or waggons about to be described; two other short rails are
placed parallel with each of these radiating rails to assist in guiding and
In
keeping the carriages or waggons in their proper places in the oven.
order to protect the turntable from the excessive action of the heat a
layer of sand is placed upon it reaching nearly to the level of the top
of the rails. These rails are in continuation of rails from the outsido
through the door of the oven. I make carriages or waggons wholly or
partly of iron or steel, or of other suitable fire-resisting material and of
segmental shape, and provided with three wheels to move in and out
of the oven on the rails above mentioned. I prefer to make the carriages
or waggons about five inches in depth. I fill them with sand and then
place thereon about twelve inches of fire-bricks, upon which I place the
pois containing the articles to be annealed, which are packed outside the
oven and the carriages are run on the rails into the oven. I prefer to
construct the turntable for six carriages or waggons. I place friction

page_text: rollers behind the carriages or waggons to prevent them rubbing against
the side of the brickwork when on the turntable. To the turntable I
attach suitable gearing, which is made to gear with a wheel attached to
an axle in connexion with gear wheels, whicli are moved by a wheel
placed at the back of the oven or kiln worked by hand or by any other
means. As the wheel is turned the turntable moves, and any particular
carriage or waggon can so soon as it arrives opposite the door be taken
out and another carriage at once inserted. The door of the oven is raised
or lowered by means of a screw gearing with wheelwork, or by any other
suitable gearing, and when shut the door is kept closed by two eccentric
cams keyed on a parallel shaft or axle, and when the door is required
to be opened or shut it is done by a lever fitting on the square end of
the shaft, and which by a half-turn either way opens or shuts the door.
I form through the outside covering and the lining of fire-bricks in one
or more convenient place or places a hole (circular or otherwise) in order
to watch the process of the work, and also to admit air into the oven, and
which I find assists the combustion. The door of this opening is placed
on an incline and requires no fixing and can be easily opened and shut.
My Invention can be more readily understood by referring to the
Drawings which accompany this Specification, and which are calculated
on the scalo of half an inch to the foot, but I wish it to be understood
that I do not bind myself to the exact shapes and dimensions shewn
therein, as these can be altered in their details as is found necessary
in practice.
Fig. 1 is an elevation of the front of the oven or kiln; Fig. 2 is a
sectional elevation of it; Fig. 3 is an elevation of the back of the oven
or kiln; Fig. 4 shews the gearing and wheelwork driving the turntable;
Fig. 5 is a ground plan of the oven or kiln; Fig. 6 is a plan of the
carriage or waggon.
A is the ascending flue; B, the descending flue to direct the heat and
flame through the oven from the right to the left, or vice versa ; C are
the carriages, which are filled with sand up to the dotted line, on the
top of which fire-bricks are placed; D shows the turntable which moves
on a centre pivot supported by wheels. This turntable is moved, as
shewn in Figs. 3 and 4. The wheel M being turned causes the gear
work to work and to turn the turntable D, with which it gears together.
The ground plan, Fig. 5, shews an oven with a turntable that will hold
six carriages or waggons; E are the fire-bars; F, the ash pan; G, the

page_text: chimney; H are the regulators or dampers for regulating the ascending
and descending flues; I are the annealing pots placed in the carriages or
waggons C. The parts of the oven marked J are built in fire-brick. K
is the gear work for raising the door N. By turning the wheel K, which
actuates the gearing attached to the door by two chains, the door is
raised or lowered at the will of the operator; L is the spy hole opening for
watching the oven and to admit air; O, O, are the rails, upon which the
carriages or waggons are. moved in or out of the oven; P are the fire-
'doors for putting in fuel; Q are the ash-pit doors provided with venti-
lators, which can be more or less opened or shut, according to the draught
required; Rare the brick foundations; S is a small door in the larger
door to put in small articles requiring only a short time to anneal. This
door is fastened with an ordinary latch. T are two eccentric cams keyed
on a parallel shaft or axle to keep the door fast.
Having now described and explained my said Invention, and the
means of carrying out the same,
1. I claim the combination of parts forming the improved anucaling
oven or kiln, constructed and arranged substantially as herein described.
2. I also claim the use of the turntable and the sectional carriages or
waggons which will resist the fire applied, as described herein.
3. I also claim the combined arrangement of gear work and rails, and
the flues and regulators (dampers) for regulating the heat and consuming
the smoke, and also the opening for watching the work and to admit
air into the oven, and the use of two eccentric cams for fastening
*the door.
In witness whereof; I, the said John Tenwick, have hereunto set
my hand and seal, this Eleventh day of September, in the year of
our Lord One thousand cight hundred and sixty-nine.