IMPROVE- MENTS IN THE ANNEALING AND TEMPERING OF GLASS, AND APPARATUS For THAT PURPOSE
Year: 1879

page_text: LETTERS PATENT to Charles William Siemens, of No. 12, Queen Anne's Gate,
Westminster, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN THE ANNEALING AND TEMPERING OF GLASS, AND APPARATUS For
THAT PURPOSE." Partly a communication from abroad by Frederick Siemens,,
of Dresden. in the German Empire.
Sealed the 1st July 1879, and dated the 20th March 1879.
PROVISIONAL SPECIFICATION left by the said Charles William Siemens at
the Office of the Commissioners of Patents on the 20th March 1879.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN THE ANNEALING AND TEMPERING OF
GLASS, AND APPARATUS FOR THAT PURPOSE." [Partly a communication from abroad
by Frederick Siemens, of Dresden, in the German Empire.
This Invention relates to a method of annealing and tempering glass by the use
of apparatus whereby time and labour are economised and the quality of the glass
is improved. Instead of placing glass ware as it is formed into stoves or annealing
ovens of considerable size, where it is allowed to cool very gradually in the usual
way, it is according to this Invention placed in a travelling chamber mounted on
wheels, which is heated to redness in a gas stove or furnace. The travelling chamber
for this purpose is in the form of a truck open at the top and at one end, and having
at the other end openings for introducing the glass ware. The truck is made of
metal lined with non-conducting material, such as sand or pottery-ware, or its sides
may have ribs projecting inwards to prevent the glass from coming into direct
contact with them. The sides of the truck have at their upper edges sand troughs
to receive projecting lips or flanges of a hood.. The truck, uncovered, is wheeled into
the gas stove, where it is heated to redness. The glass articles as they are made
are introduced into the heated truck by the openings at its end, and when the truck
is filled it is wheeled out of the stove and a hood or cover is immediately placed
upon it, the flanges or lips of the hood being immersed in the sand troughs to
:

page_text: prevent access of air. The truck thus covered is wheeled away to a convenient
place, where it is allowed to cool gradually, and after cooling its contents are
removed. By providing several trucks as described the work can be carried on
continuously, the heating, charging, cooling, and discharging of each being performed
in rotation. Glass ware treated as described receives a certain temper due to the
comparatively rapid but regular cooling, whereby its strength and power to resist
blows are considerably increased.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles William Siemens in the Great Seal Patent Office on
the 20th September 1879.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVEMENTS IN THE ANNEALING AND TEMPERING OF
GLASS, AND APPARATUS FOR THAT PURPOSE." Partly a communication from abroad
by Frederick Siemens, of Dresden, in the German Empire.
This Invention relates to a method of annealing and tempering glass by the use
of apparatus whereby time and labour are economised and the quality of the glass
is improved. Instead of placing glass ware as it is formed into stoves or annealing
ovens of considerable size, where it is allowed to cool very gradually in the usual
way, it is according to this Invention placed in a travelling chamber or furnace bed
mounted on wheels, which is heated to redness in a gas stove or furnace. The
travelling chamber or bed for this purpose is in the form of a truck, open at the top
and at one end, and having at the other end openings for introducing the glass
ware, or this may be introduced at the open end through apertures in the stove.
The truck is made of metal lined with non-conducting material, such as sand or
pottery. ware, or its sides may have ribs projecting inwards, or a double skin with
an intervening air space to prevent the glass from coming into direct contact
with the outer casing. The sides of the truck have at their upper edges sand
troughs to receive projecting lips or flanges of a hood. The truck, uncovered, is
wheeled into the gas stove, where it is heated to redness. The glass articles as
they are made are introduced into the heated truck through the openings at its
end, or in the wall of the stove, and when the truck is filled and sufficiently
heated it is wheeled out of the stove and a hood or cover is immediately placed upon
it, the flanges or lips of the hood being immersed in the sand troughs to prevent
access of air. The truck thus covered is wheeled away to a convenient place, where
it is allowed to cool gradually, and after cooling its contents are removed. By
providing a pair of kilns and several trucks with beds and hoods as described the
work can be carried on continuously, the heating, charging, cooling, and discharging
of each being performed in rotation. Glass ware treated as described can, if desired,

page_text: DESCRIPTION OF THE DRAWINGS.
Figs. 1 and 2 of the accompanying Drawings shew one arrangement of annealing
and tempering kiln or stove for carrying out the before described improved method
of annealing and tempering glass. Fig. 1 shews a section on line 1-1, Fig. 2,
which is a section on line 2-2, Fig. 1. The kiln or stove is composed of the fixed
brickwork heating chamber A, and the removeable bed or truck B in which the
glass articles to be annealed are placed. This truck is constructed of sheet metal,
the sides being provided with internal ribs B¹ to prevent the glass articles from
coming into direct contact with them, while the bottom has a layer or lining B³ of
sand or any other suitable non-conducting material; it is mounted on wheels C,
which run upon rails as shewn, so that it can be readily run into and out of the
kiln. The truck is open at the top and at its inner end, so that when in position
in the kiln the flames or hot gases issuing from the ports A¹ on either side can play
freely into and over the whole surface of the floor before escaping through the
openings A² to the chimney D. When the truck is in position in the kiln a close
joint is formed between the two by means of sand troughs E on the sides of the
truck into which clip flanges F fixed to the brickwork of the kiln. When in this
position the interior of the truck is first heated to the required temperature, and the
glass articles to be annealed and tempered are introduced into it through the
openings G, which are then closed by covers. When a truck has been filled and
the glass articles subjected to the heat of the stove for a sufficient length of time it
is withdrawn, and its open end and top are immediately closed by the hood or
cover H suspended close in front of the kiln, the flanges of which hood dip into the
sand troughs E, E¹, so as to form a close joint, and the truck thus forming a closed
chamber is then run to any convenient locality, where it and its contents are
allowed to cool. The hood H is then removed, and after the glass has been taken
out the truck is again ready for use. The combustible gas for heating the kilns
passes from the main channel I leading from a gas generator up through the flues J
to the openings A¹, where it meets the air entering through passages K. Slides L
and L are provided for regulating the supply of gas and air to the kiln, or cutting
it off when a truck is moved. The space beneath the truck B being quite open to
the atmosphere, the underframing and wheels are kept sufficiently cool to prevent
injury.
Figs. 3, 4, and 5 shew respectively a section on line 3-3, Fig. 4, a section on
line 4-4, Fig. 3, and a sectional plan on line 5-5, Fig. 3, of another form of truck
kiln according to this Invention. In this modification the truck B has no charging
openings at its front end, but is charged with glass articles through the openings M
in the end wall of the stove. It is provided with double sides B' (of which the
inner may be perforated), with an intervening air space, by which the glass articles
are prevented from becoming unequally cooled by direct contact with the outer
skin, which is cooled by the atmosphere. The gas and air ports A' in this arrange-
ment are at the front end of the kiln, J and K being respectively the gas and air
flues leading to them, and the chimney flue A² is at the back end. The other parts
are similar to those previously described, and are indicated by similar letters of
reference.
Figs. 6 and 7 shew respectively a section on line 6-6, Fig. 7, and a section on
line 7-7, Fig. 6, of another form of truck kiln. In this arrangement the truck B
is placed almost entirely outside the brickwork chamber A of the kiln, the hood H
serving as the covering to the truck while it is subjected to the action of the flame.
For this purpose it is hinged at H¹ to the truck, and is maintained in the raised
position indicated by means of catches H holding arms H³ projecting therefrom,

page_text: the spaces between the sides of the hood and of the brickwork of the kiln when the
truck is in position are closed by strips of iron laid over them. On completion of
the heating process the catches are thrown out and the hood allowed to fall so as to
close the truck; immediately on its removal from the kiln the hinged end plate or
flap N having been first raised, as shewn in Fig. 7, so as to be held by the edge of
the hood falling over it. The glass articles to be annealed are introduced into the
truck through openings M, as previously described with reference to Figs. 3, 4, and
5. The gas and air ports A¹ project from the bed of the kiln instead of. being
formed in the sides thereof, and the air passages thereto lead from the inner face of
the brickwork, beneath the truck B, so that the currents of air in passing into them
assist in cooling the framing and the wheels of the truck. The slides L and L¹ serve
respectively to cut off or regulate the gas and air supply. The close joint between
the brickwork and the truck is in this case. effected by means of sand troughs O
fixed to the brickwork, into which dip flanges projecting from the sand troughs E
on the sides of the truck that serve to make the joint with the cover. The cover H,
as well as the sides B', are in this case double, with intervening air spaces, as before
described. The parts similar to those already described are marked by similar
letters.
་
In operating with kilns such as have been described two may be arranged side
by side, so that while the truck in one is receiving glass articles to be annealed a
filled truck may be removed from the other and an empty truck may be introduced
and heated preparatory to receiving a charge. In this manner the annealing and
tempering of glass can be carried on continuously, and a large quantity may be
annealed and tempered by means of a pair of comparatively small kilns. Sets of
three or more kilns can likewise be worked in rotation. The glass articles to be
annealed and tempered can be packed in tiers on the trucks when they are of such
form or character as to admit of it, care being taken that they do not touch the
outer skin.
'
Having thus described the nature of the said Invention and in what manner the
same is to be performed, I would have it understood that I make no general claim
to the use for annealing glass of trucks that can be wheeled into a stove or kiln,
nor to charging such trucks while they are in the kiln, nor covering them when
removed therefrom for cooling, but I claim,-
'
The use for annealing and tempering glass of a kiln consisting partly of stationary
structure provided with suitable furnace flues and partly of a truck which, being
wheeled into position so as to form the bed of the kiln exposed to the direct action
of the flame, receives its charge of articles to be annealed and tempered, and which
being wheeled out of the kiln and covered against access of air forms a close
chamber wherein the said articles become gradually cooled, substantially as herein
described.
In witness whereof, I, the said Charles William Siemens, have hereunto set
my hand and seal, this Nineteenth day of September, in the year of our
Lord One thousand eight hundred and seventy nine.