Improvements in Glass-annealing Furnaces or Leers.
Year: 1897

page_text: Date of Application, 20th Aug., 1897
Complete Specification Left, 20th May, 1898- Accepted, 9th July, 1898
PROVISIONAL SPECIFICATION.
Improvements in Glass-annealing Furnaces or Leers.
I, WILLIAM PRESTON, of Eccleston Arms Hotel, Prescot Road, St. Helens, in
the County of Lancaster, Late Manager of Glass Works, do hereby declare the
nature of this invention to be as follows:-
This invention relates to the annealing of glass particularly plate glass, but
also applicable for other glass goods, and its object is to provide a furnace or leer
whereby the process of annealing may be continuously carried on and a great
saving in time effected. Various attempts have hitherto been made to anneal
glass by a continuous process, but same have met with little or no success.
My invention consists first in combining with a kiln or settling arch two re-
ceiving chambers at one end, and a graduated or cooling off leer at the other
end, and second in means for moving the glass through the leer.
In carrying out the invention, any size and shape of plant may be adopted
according to particular requirements, but I prefer to place the kiln and graduated
leer together in the form of an L and to place the two receiving chambers one
at each side of the receiving end of the kiln. In the front of each receiving
chamber, I provide suitable entrance holes for the glass and furnish same with
drop doors or the like for excluding cold air said doors being preferably formed
of brick in an iron frame. In the side of said chambers, I form pushing holes
to admit push rods by which the glass may be pushed into the kiln, and similar
holes in the kiln whereby the glass may be pushed successively down the kiln
and then into the leer. These push-holes are preferably formed as large aper-
tures bricked up to leave only a small hole for the push rod. This allows of the
bricks being taken out and the whole aperture rendered available to afford access
to the interior in case of repairs.
Any suitable means for heating the kiln may be adopted, and I provide, at
suitable points in the cooling off leer, air orifices with dampers whereby the
temperature may be regulated and a suitable graduation effected from the kiln
entrance to the leer exit.
The means for moving the glass through the cooling off leer consists of a
number of rails placed in the bed of the leer which is formed of grooved tiles
or the like for the purpose, to which rails a reciprocating movement is given by
any known devices in such a way that the rails make their return movement at
a lower level than their outward movement by sinking into the grooves. The
glass plates or the trays containing the glass goods are thus lifted from the floor
by the rails and carried along with them, then deposited on the bed when the
rails sink into the grooves to make a return movement, after which the rails
again rise and the glass plates are again lifted and forwarded a step further and
so on. In order to obtain this movement of the rails, however, I prefer instead
of the usual arrangement to mount them on numerous elbow levers carried by
rock shafts which are preferably counterweighted and linked together so as to
receive a movement in common from an eccentric or the like at the end of the

page_text: leer. These levers carry grooved pulleys on which the rails rest, and the latter
are connected with suitable eccentrics or the like on a driving shaft at the exit
of the leer. The rails are thus given a reciprocating movement, and by means
of said levers, are raised on their outer stroke and lowered on their inner stroke.
I prefer to operate the link of the elbow levers by means of worm-gearing and a
hand wheel and to operate the rails by means of chains arranged to wind on drums
mounted on a shaft which may be turned by hand or by power. The chains are
so connected as to pull the rails backwards or forwards according to the direction
in which the drum shaft is turned. In use the rails are first lifted out of the
grooves by means of the worm gearing and elbow levers, and the drum then
operated to draw the rails and therewith the glass to the desired extent. The rails
are then lowered and again returned by turning first the worm gear and then
the drum shaft in a reverse direction.
In operation, the glass is fed alternately into the receiving chambers which
are the hottest part of the kiln, the glass being pushed into the kiln from one
chamber, whilst the other chamber is being fed. By this means, each plate or
batch may be heated for a short time in the receiving chamber to counteract any
chill received whilst being fed in. The glass plates or trays of glass goods are
thus pushed into the kiln, the plates from the one receiving chamber being pushed
down one side of the kiln at suitable distances apart and those from the other
chamber being similarly pushed down the other side of the kiln, the push rods
being made to reach to each plate separately, whilst in the case of trays containing
glass goods the same are caused by their gradual accession to move down the
kiln to the leer where the plates or trays are pushed on to the reciprocating rails
and carried along to the discharge, where a swivel table or other suitable ineans
will be arranged to receive the plates or trays at exit end. The plates are thus
afforded time to gradually die down in the kiln and are gradually cooled off in
the leer.
In some cases I may provide the kiln or settling arch with rails and operating
devices for moving the glass as herein before described with reference to the gradu-
ated leer.
Dated this 19th day of August: 1897
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Patent Agents for the Applicant.
Improvements in Glass-annealing Furnaces or Leers.
I, WILLIAM PRESTON, of Eccleston Arms Hotel, Prescot Road, St. Helens, in
the County of Lancaster, Late Manager of Glass Works, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the followings statement:-
This invention relates to the annealing of glass, particularly plate glass, but is
also applicable for other glass goods, and its object is to provide a furnace or leer
whereby the process of annealing may be continuously carried on and a great
saving in time effected. Various attempts have hitherto been made to anneal
glass by a continuous process, but same have met with little or no success.
My invention consists first in combining with a kiln or settling arch two re-
ceiving chambers at one end, and a graduated or cooling off leer at the other
end, and second in means for moving the glass through the leer.

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drawings, in which :-
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accompanying
settling arch
Figure 1 is a horizontal section or plan of the plant, the kiln or
and the leer being broken away to bring them within the limited dimensions of
the sheet;
Figure 2 a front elevation of the kiln or settling arch;
Figure 3 a side elevation, looking from the left hand side of Figure 1;
Figure an elevation of one side of the leer with the settling arch in cross
section;
Figure 5 a sectional view illustrating the manner of lifting the glass from its
bed and moving the same through the leer;
Figure 6 a vertical cross section of the leer, showing the bed and the lifting
devices.
Figure a vertical cross section of the leer through the flue leading to the
chimney.
Figure 8 a cross section of Figure 7.
In carrying out the invention, any size and shape of plant may be adopted
according to particular requirements, but I prefer to place the kiln and graduated
leer together in the form of an L and to place the two receiving chambers one
at each side of the receiving end of the kiln. This arrangement is shown in
Figure 1, in which 1 is the kiln or settling arch; 2 and 3 the receiving chambers;
and 12 the leer. In the front of each receiving chamber 2 and 3, I provide
suitable entrance holes 5 for the glass and furnish same with drop doors or sliding
fronts 6 or the like for excluding cold air, said doors being preferably formed of
brick in an iron frame (Figures 1 and 2). In the side of said chambers 2 and 3,
I form pushing holes 7 to admit push rods by which the glass may be pushed
into the kiln, and similar holes and 4 in the kiln whereby the glass may be
pushed successively down the kiln and then into the leer. These push-holes are
preferably formed as large apertures bricked up to leave only a small hole for
the push rod (Figures 2 and 3). This allows of the bricks being taken out and
the whole aperture rendered available to afford access to the interior in case of
repairs.
Any suitable or usual means for heating the kiln may be adopted, and I
provide, at suitable points air admission orifices whereby the temperature may
be regulated and a suitable graduation effected from the kiln entrance to the
leer exit. This admission of air is preferably effected by means of arches or
flues 8 and 29 formed beneath the floor of the kiln 1, and leer 12 respectively.
These arches are useful not only for admitting cool air beneath the floors or beds
of the kiln and leer, but also for preventing moisture from finding its way from
the ground to the beds or floors of these chambers. In practice it is found con-
venient to brick up the ends of these flues or arches and from the air admission
orifices by leaving out one brick or more, according to the amount of air deemed
best to be admitted. By inserting a brick or bricks, or a piece of a single brick,
the orifice may be readily reduced in size. Dampers may however be employed,
if preferred, to control the air admission.
To ensure the proper flow of heated air from the forward end of the kiln 1,
through the same and thence through the leer, there is provided at the rear end
of the latter, a series of outlets 30 (Figures 7 and S) which communicate with a
flue 31, in turn connected with a stack or chimney 32 (Figures 1, 7 and 8). This
may be a stack used in connection with other portions of the glass plant, or a
special one, as found convenient in any given case. A valve or damper 33, serves
to regulate the strength of the draft or current.
At suitable points in the length of the leer, vertically adjustable plates 34
(Figures 4, 5 and 6) are provided by which the heated air may be caused to impinge
more or less directly upon the glass, or permitted to flow freely along the upper
part of the arch, with comparatively little effect upon the glass. Rods or pins 35

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adjusted in any convenient manner.
The side walls of the structure may be stayed by uprights 10, connected by
tie rods 11, or otherwise constructed.
Suitable openings may be formed at intervals in the side walls of the leer 12
and provided with doors 35 (Figures 1 and 4) to permit ready access to the interior
thereof.
The means for moving the glass through the cooling off leer consists of a
number of rails placed in the bed of the leer which is formed of grooved tiles
or the like for the purpose, to which rails a reciprocating movement is given by
any known devices in such a way that the rails make their return movement at
a lower level than their outward movement by sinking into the grooves. The
glass plates or the trays containing the glass goods are thus lifted from the floor
by the rails and carried along with them, then deposited on the bed when the
rails sink into the grooves to make a return movement, after which the rails
again rise and the glass plates are again lifted and forwarded a step further and
80 on. For this purpose the leer is of special construction, having a bed or floor 13,
(Figures 1 and 0) grooved or channelled to receive a series of rails 14, which are
placed parallel to one another and are connected at their outer ends to a bar or
cross head 15, by which they may be moved in unison. The rails lie normally
flush with or slightly below the surface of the bed 13, being supported by grooved
rollers 16, carried by arms 17, projecting from rockshafts 18 extending transversely
across the leer, beneath its bed or floor, as seen in Figures 1, 4, 5 and 6. The
rockshafts are provided with radial arms or levers 19, which are connected by rods
or links 20, so that all the shafts may be rocked simultaneously and equally,
thus lifting their rollers 16 in the same time and to the same extent, and conse-
quently elevating the entire bed of rails in every portion alike. By sufficiently
rocking the shafts 18, the rails will be carried above the bed or floor of the leer,
and thus the plates, sheets or trays lying upon the bed or floor will be lifted off
the floor and held upon the rails alone. To facilitate the lifting of the rails
and the bodies lying on the bed or Hoor, the rockshafts may be provided with
counterbalanced arms 21, projecting therefrom on the opposite side of their axes
from that occupied by the roll-carrying arms 17.
The load to be lifted in such a leer frequently amounts to a number of tons,
and it is therefore necessary to provide mechanism affording the leverage or power
necessary to lift such a load, less the off-set afforded by the counterbalances. A
convenient means for the purpose is illustrated in Figure 4, where a toothed
sector 22 is shown secured to one of the rods or links 20, and arranged to mesh
or engage with a worm or screw 23, by which the sector may be swung about
its axis 37. This construction affords adequate power, the screw being furnished
with a hand wheel 24 of adequate size for the purpose. Obviously, any other
convenient means may be substituted, or the rock-shafts may be turned by power.
If preferred the rollers 16 may be carried by vertically movable yokes, lifted by
eccentrics, toggles, or equivalent devices of any known construction.
While the rails are in their elevated position and the glass or the trays con-
taining glass articles are thus lifted off the bed or floor, the rails are moved longi-
tudinally, rearward as hereinafter described, thereby carrying all the contents
of the leer in that direction a distance equal to the movement of the rails. When
the necessary travel is effected, the rollers 16 are lowered to their normal position
by turning the worm or screw 23 backward, and the rails are permitted to fall
below the surface of the bed or floor, after which they are moved longitudinally
inward, to their first position, preparatory to a second elevation and outward
movement. In this way the glass within the leer is lifted from the bed, advanced
a given distance, and set down upon the bed or floor in its new position, and
this operation is repeated as often and to as great an extent as required by the
circumstances of the case.
Various mechanisms may be employed to effect the longitudinal movement of

page_text: the rails or rail-bed, but that represented in Figures 1, 4 and 5 will be found
simple and effective. This comprises a horizontal shaft 25, extending across
the end of the leer, below the level of its bed or floor, and carrying either a con-
tinuous drum or a series of short drums 26, about which are wrapped or wound,
chains or flexible bands 27, the opposite ends of which are attached to the cross-
head 15, and to the rails 14, at points sufficiently separated to permit the requisite
travel of the rails. When the shaft and drums are turned in one direction they
move the rails to the rear, and when turned in the reverse direction they return
the rails inward to their first position, as will be readily understood upon referring
to Figure 5.
The shaft 25 is furnished with a hand wheel 28, by which to turn it, or it may
be driven by power if desired.
The lever system by which the rockshafts are turned, is advisably, enclosed by
a casing at the sides of the kiln as indicated in Figure 6, to prevent undue ingress
of air into the kiln, and to prevent drafts. Suitable doors or openings must how-
ever be provided in said casing to afford access to the arches or other parts of the
sides of the kiln where required.
In operation, the glass is fed alternately into the receiving chambers which
are the hottest part of the kiln, the glass being pushed into the kiln from one
chamber, whilst the other chamber is being fed. By this means, each plate or
batch may be heated for a short time in the receiving chamber to counteract any
chill received whilst being fed in. The glass plates or trays of glass goods are
thus pushed into the kiln, the plates from the one receiving chamber being pushed
down one side of the kiln at suitable distances apart and those from the other
chamber being similarly pushed down the other side of the kiln, the push rods
being made to reach to each plate separately, whilst in the case of trays containing
glass goods the same are caused by their gradual accession to move down the kiln
to the leer where the plates or trays are pushed on to the reciprocating rails and
carried along to the discharge, where a swivel table or other suitable means usual
in annealing furnaces is arranged to receive the plates or trays at exit end. The
plates are thus afforded time to gradually die down in the kiln and are gradually
cooled off in the leer.
It will be seen that by means of the two heating or receiving chambers 2 and 3
which may be used alternately, the kiln may be fed more rapidly than would
otherwise be practicable. Also that either chamber, or the heating apparatus
thereof, may at any time be repaired without necessitating any interruption in
the use of the kiln.
In some cases I may provide the kiln or settling arch with rails and operating
devices for moving the glass as hereinbefore described with reference to the
graduated leer.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. The improvement in glass-annealing furnaces or leers, which consists in pro-
viding the kiln or settling arch with two receiving chambers arranged one on
each side of its forward or hottest end and adapted to be fed alternately whereby
the glass may be given a preliminary heating and be fed rapidly into the kiln,
substantially as herein beforo described.
2. In a glass-annealing furnace or leer: the combination with a kiln or settling
arch, of two receiving chambers arranged one on each side of its forward or
hottest end, and a cooling-off leer arranged at its other or cooler end at right
angles to the kiln, substantially as herein before described.
3. In a glass-annealing furnace or leer; forming the floor or bed with longi-
tudinal grooves or channels, and mounting in said grooves a series of rails on
grooved rollers carried by levers or radial arms fixed on a series of rock-shafts
arranged transversely in or beneath the floor or bed, said rock-shafts being coupled

page_text: together to have a similar and equal movement and having suitable means for
oscillating them in both directions to raise and lower the rails and therewith
the glass lying on the floor or bed, and the rails being connected at one end to
a cross-head or bar and provided with means for moving them and therewith
the glass over the rollers when lifted by the rockshafts, and for returning them
but not the glass when lowered into the grooves by the rock-shafts whereby the
glass may be shifted step by step through the leer or kiln substantially as herein-
before described.
4. In a glass-annealing furnace or leer such as described, having its floor or
bed grooved to receive a series of rails supported by levers or radial arms on a
series of coupled transverse rock-shafts as a means of shifting the glass step by
step; the arrangement of worm gearing for oscillating the rock-shafts in both
directions to raise and lower the rails, and of a windlass or winding drums with
chains or bands for moving the rails longitudinally in one or the other direction
according to the direction in which the windlass is rotated, substantially as herein-
before described.
5. The general construction and combination of parts, taken as a whole, forming
the improved glass-annealing furnace or leer, substantially as hereinbefore
described and illustrated.
Dated Is 5th day of alay 1000.
W. P. THOMPSON & Co.,
Patent Agents,
Of Liverpool, Manchester, Birmingham and London.